Low Power Conditions Research Articles

Social Power May Enhance Workplace Initiative: An Experimental Investigation Among Two Samples.

Organizational citizenship behavior (OCB) refers to voluntary actions members take to benefit organizational function. However, the benefits of OCB for organizations are sometimes countered by detriments for employees who exhibit them, resulting in threats to organizational members' psychological wellbeing. The present research examined whether social power-the perceived ability to control allocations and outcomes in a social hierarchy-could increase OCB endorsement while buffering against negative personal costs. Indeed, manipulated social power enhanced OCB endorsement. This effect was mediated by increased positive affect and goal seeking among participants assigned to a high-power condition relative to participants assigned to a low-power condition. Further, participants assigned to a high-power (vs. low-power) condition did not report increased occupational burden despite their greater OCB endorsement. Patterns of results were similar among a sample of community members (N = 149; Mage = 37 years) and a sample of university students (N = 129; Mage = 20 years). Organizations might empower members by employing procedural justice principles that facilitate members' meaningful contributions to workplace operations.

Study of Solvent Dependent on Third-Order Nonlinear Optical and Thermo-Optic Coefficient of Malachite Green Dye.

This study reveals the solvent dependent third-order nonlinear optical (NLO) features of malachite green (MG) dye using Z-scan technique. MG dye is dissolved in polar solvents, including DMF, DMSO, ethanol, acetone, methanol, and 1-propanol. The study employs the Z-scan instrument, using a continuous wave (CW) laser as the excitation source, operating at a wavelength of 650nm. The closed aperture (CA) and open aperture (OA) Z-scan techniques are used to assess the nonlinear indices of refraction (n2) and nonlinear coefficient of absorption (β) of MG dye. MG dye demonstrates both saturable absorption (SA) and reverse saturable absorption (RSA) in the OA Z-scan results, due to negative and positive NLO absorption coefficients. MG dye proves a self-defocusing NLO refractive index while operating under low-power conditions. The third-order NLO susceptibility (χ3) of MG dye in various liquids are calculated to be the order of 10-6 esu. Multilinear regression fit is applied here to investigate the various intermolecular interactions between the solute and solvent. MG dye exhibited large thermo-optic coefficient of the order of 10- 3 K- 1 is observed. The results give important new information about the characteristics of MG dye and indicate potential sources of material for NLO applications in future.

The effect of apparent Police power at demonstrations against right-wing populism on Protestors' resistance using a virtual reality experiment.

Based on the Elaborated Social Identity Model of Crowd Behaviour, we tested in two experiments whether a forceful display of police power increases perceptions of illegitimacy of the police and the formation of resistance among protestors. In the high power condition, the police were dressed in riot gear (with helmets, armed with shields and batons). In the low power condition, the police were dressed in regular uniforms. In both studies, people participated in a demonstration against right-wing populism using a virtual reality setting and were either stopped by the police in riot gear or by the police in regular uniforms. The results of Study 1 (N = 155) show that the police in riot gear were evaluated as more illegitimate compared to the police in normal clothing. The results of Study 2 (N = 97) replicated this finding and illustrated that police in riot gear (compared to regular uniforms) increased protestors' intentions to engage in direct resistance against the police. This effect was mediated by perceptions of illegitimacy and anger directed at the police. Furthermore, weakly identified protestors were particularly affected by the display of power and were more likely to engage in anti-police resistance and collective action. Implications are discussed.

A Novel Energy-Aware Path Planning by Autonomous Underwater Vehicle in Underwater Wireless Sensor Networks

Wireless sensor networks can monitor the environment to detect anomalies and reduce the risk of maritime traffic. Energy is necessary for low-power conditions where wireless sensor networks are used. Ensuring the lifespan of energy constraints and providing continuous environmental observation, data collecting, and communication requires management. Battery replacement and energy consumption issues can be resolved with path planning and energy-efficient autonomous underwater vehicle charging for sensor nodes. The nearest neighbour technique is used in this study to solve the energy-aware path planning problem of an autonomous underwater vehicle. Path planning simulations show that the nearest neighbour strategy converges faster and produces a better result than the genetic algorithm. We develop robust and energy-efficient path-planning algorithms that efficiently acquire sensor data while consuming less energy, allowing the monitoring system to respond to anomalies more rapidly. Increased sensor connectivity lowers energy usage and increases network longevity. This study also considers the situation when it is recommended to avoid taking direct travel paths between particular node pairs for a variety of reasons. This recommendation is considered in this study. We present a strategy based on a modified Nearest Neighbour-based Approach from the Nearest Neighbour method to address this more challenging scenario. The direct pathways between such nodes are constrained within the context of this technique. The modified version of Nearest Neighbor-based approach performs well even in that particular situation.

Recent progress of JT-60SA project toward plasma operation

Abstract Superconducting tokamak JT-60SA plays an essential role in fusion research and development by supporting and complementing ITER project, providing directions to the DEMO design activity and fostering next generation scientists and engineers. Since the incident of the Equilibrium Field coil #1 during the Integrated Commissioning (IC) in March 2021, both EU and JA Implementing agencies (IAs) have examined how to ensure safety operation of JT-60SA by mitigating the risk of possible discharge occurrence inside the cryostat. Based on the experience of the Global Paschen tests, the IAs have established a strategy of risk mitigation measures, which is a combination of (i) reinforcement of insulation, (ii) avoiding unnecessary voltage application to the coil systems and (iii) immediate de-energization of the coils when deteriorated vacuum condition is detected. Thanks to the considerable efforts of the Integrated Project Team (IPT) members, the IC restarted in May 2023. After the confirmation of superconducting state of coil systems (TF, EF and CS), the coil energization test and the plasma operation (OP-1) starts. The first plasma was successfully achieved on 23 October 2023 with a limited value of applied voltage and current to the coils. The plasma configuration control will be also confirmed with low plasma current and low auxiliary heating power conditions. Based on the IO-F4E-QST collaboration, activities of JT-60SA have been shared with the IO and provided an important lesson learned for ITER assembly and commissioning, and will provide an outstanding contribution to fusion research at large. After OP-1, Maintenance & Enhancement phase 1 (M/E-1) starts from January 2024, in which in-vessel components are installed, and heating system and diagnostic system are extensively upgraded to allow high power heating experiment planned in OP-2. In order to make the best use of JT-60SA, newly organized JT-60SA experiment team will refine the research plan in the future high heating power operation phase.

Microstructural analysis and defect characterization of additively manufactured AA6061 aluminum alloy via laser powder bed fusion

AA6061 is a widely used aluminum alloy with significant applications in the aerospace and automotive industries. Despite its popularity, the utilization of additively manufactured AA6061 through the laser powder bed fusion (LPBF) process has been hindered by the pronounced formation of pores and cracks during rapid solidification. This study quantitatively investigated defects, including pores and cracks, and microstructures, including texture, grain size, subgrain structure, and precipitates, of LPBF-manufactured AA6061 across a broad spectrum of laser power and speed combinations. A high relative density of more than 99 % was achieved with a low-power and low-speed condition, specifically 200 W and 100 mm/s, with minimal cracks. Large pores, akin to or exceeding melt pool dimensions, emerged under either low or high energy densities, driven by the lack of fusion and vaporization/denudation mechanisms, respectively. Solidification cracks, confirmed by the fractography, were propagated along grain boundaries and are highly dependent on laser scanning speed. Elevated power and speed exhibited finer grain size with refined subgrain cellular structures and increased precipitates at interdendritic regions. The cooling rate and thermal gradient estimated from thermal analytical solutions explain the microstructures’ characteristics. Nano-sized Si-Fe-Mg enriched precipitates are confirmed in both as-built and heat-treated conditions, whereas T6 heat treatment promotes a uniform distribution with coarsening of those precipitates. The low-power and low-speed conditions demonstrated the highest yield strength, consistent with defect levels. A minimum of 102.3 % increase in yield strength with reduced ductility was observed after heat treatment for all examined conditions. This work sheds light on printing parameters to mitigate the formation of pores and cracks in additively manufactured AA6061, proposing a process window for optimized fabrication and highlighting the potential for enhanced material properties and reduced defects through process control.

A 28-47.5 GHz broadband power amplifier using improved MCR technique in 40-nm CMOS

This paper presents a broadband power amplifier (PA) implemented in 40-nm CMOS process for low power application. The PA cascades two stages of common-source differential transistors and adopts symmetrical magnetically coupled resonators (MCRs) for impedance matching and single-ended differential conversion. Theoretical analysis elucidates the effect of the resonator Q on the frequency response of the transformer, thus giving the distribution of the poles and their precise locations, and revealing the quantitative relationship between bandwidth and gain ripple. A method for efficiently balancing gain ripple and bandwidth in k, Q space under low-power conditions when the intrinsic Q of the source impedance is high is described in detail. Measurement results demonstrate a 51.6% 3-dB bandwidth from 28 to 47.5 GHz. The PA achieve 10.7 dBm Psat, 8.5 dBm OP1db and 23% peak PAE at 31 GHz.

Influence of high-reactivity energetic materials on microstructure and performance on iron-based cladding layer under low laser power

Abstract Under low laser power conditions, the cladding layer is constrained by inadequate energy density, resulting in incomplete melting of certain powder particles and the occurrence of defects such as cracks and pores within the layer. This paper utilizes a QT500 substrate and synergistically integrates high-reactivity energetic materials (H-REMs) with metal powder. By external laser energy ignition, the localized combustion of the H-REMs (Al + Fe2O3) is induced, thereby providing additional heat input during the laser cladding process. Through in-depth analysis of extensive experimental data, the influence of H-REMson microstructure and performance of alloy cladding layerhas beenrevealed. The research results demonstrate that the inclusion of H-REMs leads to a 450 K increase in the maximum temperature of the molten pool. By incorporating high-reactivity energetic materials, the energy density utilization of the composite material increased from 0.2663 to 0.7375. The combustion wave generated by H-REMs induces mixing in the molten pool, resulting in cladding layer grain refinement and an average hardness increase of 80 HV1. The friction coefficient decreases from 0.71024 (prior to the addition of H-REMs) to 0.35809, representing a reduction of approximately 49 %.

Enhanced growth rates of N-type phosphorus-doped polycrystalline diamond via in-liquid microwave plasma CVD

Phosphorus-doped diamond (PDD) exhibits excellent properties, making it suitable for a wide range of applications, such as electronic devices and electrodes. Here, we report the first synthesis of PDD by in-liquid microwave plasma CVD (IL-MPCVD) under high-pressure and low-power conditions. A mixture of methanol (MeOH) and ethanol (EtOH) with triethyl phosphate ((C2H5)3PO4) and (P/C = 1000 ppm) was used for the PDD deposition. Samples were characterized by laser microscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. Notably, PDD was successfully produced at a growth rate of 280 μm/h, which is two orders of magnitude higher than conventional CVD methods. Additionally, cyclic voltammetry (CV) and impedance spectroscopy (EIS) were used to evaluate the electrochemical properties of PDD. As a result, we confirmed the wide potential window characteristic of conductive diamond and determined that the donor density was [P] = 3.8 × 1017cm⁻³. Therefore, it is clear that IL-MPCVD is applicable for very high growth rates in the CVD process for PDD synthesis.

Research on high-speed digital optical signal jitter measurement technology based on clock recovery algorithm using eye diagram opening area

With the rapid development of information technology, high-speed digital optical signal transmission technology has become the core of modern communication networks. However, the increase in transmission rates brings challenges such as noise, distortion, and interference, which affect the accuracy of clock recovery. To address these issues, this study proposes a clock recovery algorithm based on the eye diagram opening area to improve the accuracy and efficiency of high-speed digital optical signal jitter measurement. The proposed method extracts clock information from the signal using the opening area and curvature characteristics of the eye diagram for jitter measurement. Experimental results demonstrate that the clock recovery algorithm based on the eye diagram opening area can stably reconstruct the signal eye diagram and obtain jitter parameters under different optical power conditions. At optical powers of −7.2 dBm, −12.2 dBm, and −17.2 dBm, the Q-factors were 8.8, 7.6, and 4.3, respectively, and the RMS jitter values were 12.2 ps, 13.4 ps, and 21.2 ps, respectively. At optical powers of −2.3 dBm, 0.1 dBm, 2.4 dBm, 4.6 dBm, and 6.0 dBm, the Q-factors were 9.1, 9.3, 9.5, 9.7, and 10.0, respectively, and the average jitter values were 8.9 ps, 8.5 ps, 8.0 ps, 7.5 ps, and 7.0 ps. These results indicate that the proposed algorithm performs excellently under low optical power conditions and maintains high recovery accuracy even when jitter increases at higher optical powers. The clock recovery algorithm based on the eye diagram opening area significantly improves the accuracy and stability of high-speed digital optical signal jitter measurement, enriches the theoretical research of clock recovery algorithms, and shows significant advantages in improving signal transmission quality, reducing bit error rate, and enhancing communication link reliability. The research outcomes provide key technical support for the optimization of modern high-speed optical communication systems.

TROG: a fast and robust scene-matching algorithm for geo-referenced images

ABSTRACT In a GNSS-denied/challenged environment, the scene-matching navigation system (SMNS) is a vital autonomous technology for unmanned aerial vehicles (UAV). This paper proposes a novel template-matching framework for multimodal images since UAV navigation requires precision and real-time performance while utilizing onboard computers with low computational power. Specifically, first, the local descriptor is extracted to form a pixel-wise feature representation of an image. Then, the Fast Fourier Transform is applied to measure the similarity based on the feature representation. In the feature extraction part, a gradient-like pixel-level feature descriptor is designed, which is reconstructed by weighting it according to the gradient-like angles, named the three-dimensional reconstruction oriented gradient-like (TROG) descriptor. An optimized similarity measurement template is introduced in the matching part, which improves the traditional feature-based similarity measurement algorithm defined using Fast Fourier Transform (FFT) in the frequency domain. This strategy eliminates redundant computations during the matching process. To verify the effectiveness of the proposed algorithm, satellite imagery data from Google Earth are used as a reference images, and sensed images (including optical, IR, SAR, and Hyperspectral) are captured by UAV and satellites for image matching to testify to the registration accuracy, robustness, and computational efficiency. The experiment demonstrates that TROG is accurate, robust, and attains high real-time performance, making it applicable to UAV navigation and positioning. Additionally, field-flight experiments evaluate scene-matching navigation under satellite-denied conditions and low computational power conditions for UAVs, demonstrating that our scene-matching navigation system can achieve precise positioning with a positioning error of less than 1.637 m, which is comparable to satellite/inertial navigation systems. The experimental results from outdoor flight experiments highlight the value of our proposed algorithm in engineering applications under satellite denial conditions.

Microwave-assisted utilization of kraft lignin-derived activated carbon for efficient dye removal

The use of conventional petrochemical-based carbon precursors, high-energy pyrolysis-based carbonization processes, and difficulties in designing sustainable processes using activated carbon have hampered the sustainable production of activated carbon and its use in wastewater treatment processes. In this study, to overcome these limitations in the production and application of existing petrochemical-based activated carbon as a water treatment material, biomass-based kraft lignin was used as an eco-friendly carbon precursor. In addition, to increase process efficiency, activated carbon was prepared using energy-intensive microwave-assisted carbonization and applied to the dye wastewater removal process. First, kraft lignin was successfully converted into microporous activated carbon within 10 min through microwave-assisted carbonization and chemical activation processes. As a result, kraft lignin-derived activated carbon showed excellent adsorption capacity for MB of 543.82 mg/g and AO of 548.54 mg/g, respectively. In addition, through heat treatment using microwaves (low power conditions of 450 W, treatment within 2 min), it was possible to successfully achieve thermal decomposition of the adsorbed dye and recovery of the pores and texture properties of activated carbon. Finally, kraft lignin-derived activated carbon showed an excellent reuse efficiency of more than 97 %, even under the condition of reuse 5 times.

Novel Integrated Zeta Inverter for Standalone Applications

In recent years, distributed generation systems based on renewable energy sources have gained increasing prominence. Thus, the DC/AC converters based on power electronics devices have become increasingly important. In this context, this article presents an integrated Zeta inverter for low-power conditions, which operates in continuous conduction mode (CCM), achieving efficiency greater than 95%. The proposed topology is composed of four power switches, two operating at high frequency and two operating at low frequency, i.e., at the output frequency. Compared with the topologies in the literature, these configurations make it a competitive solution from the point of view of efficiency, number of elements, and, consequently, implementation cost. The proposed converter operates as a sinusoidal voltage source for local loads and is supplied by a DC source, such as batteries or a photovoltaic array. A multi-resonant voltage controller was used to guarantee the sinusoidal voltage provided to the non-linear load while dealing with the complex dynamics of the Zeta converter in the CCM. Experimental results from a 324 W prototype show the converter’s implementation feasibility and the high efficiency of the DC/AC conversion.

Enhanced trapping properties of coupled plasmonic tweezers via plasmon-exciton interaction.

Excited plasmonic nanoantennas enable the manipulation of photons coupled with quantum emitters or the trapping of particles as plasmonic tweezers, leveraging the strong evanescent gradient fields at the nanoscale. However, the ohmic loss of metals presents a significant challenge for the stable and high-precision manipulation of nanoparticles without causing damage. In this study, we investigated the enhanced trapping properties induced by plasmon-exciton interaction for coupled plasmonic tweezers. Through the coupling between plasmons and excitons, dynamic particle trapping is achievable under low excitation power conditions of 0.45 mW, with the trapping stiffness increasing by nearly 20 times. Furthermore, the trapping stiffness can be fine-tuned by modulating the quantity of excitons to regulate the coupling strength. Coupled plasmonic tweezers offer an effective strategy to mitigate the influence of ohmic loss on trapping performance, by manipulating particles with minimal laser power. These findings provide insights into enhancing trapping performance through plasmon-exciton coupling, with potential applications in biomedicine and quantum information science.

Single-photon lidar depth imaging based on sparsity adaptive matching pursuit method

Photon counting lidar has the ability to detect weak echo photons. However, in imaging applications, a small number of echo signals obtained in a very short acquisition time cannot get an accurate image estimation through the photon arrival time distribution histogram. Therefore, high-precision and fast imaging of an object using a small amount of weak echo photon signals is urgent to be solved. In this work, a sparse adaptive matching pursuit (SAMP) algorithm is proposed to process the echo photons without prior information to obtain the effective photon interval, which improves the reconstruction quality and imaging speed. By constructing a non-coaxial scanning imaging system to detect the face model, it has been experimentally proven that the proposed algorithm can achieve depth and reflectance image estimation under the condition of low power and low acquisition time of 4µs per pixel on average, and the mean absolute error (MAE) value is reduced by about 10 times compared to conventional reconstruction algorithm.

Diagnosis of multiple gases using a multi-pass ring cavity to enhance Raman scattering

Spontaneous Raman scattering is widely used to enable simultaneous concentration measurements of all relevant species with overcomes whose signal is weak and susceptible to fluorescence interference. A multi-pass ring-cavity scheme is proposed to enhance Raman scattering signal. The Raman spectra of CO2, N2, O2 and H2O in the air are acquired under condition of low excitation power which is 200 mW laser of 532 nm. Compared with the results obtained by single collection without ring cavity, the Raman signal level is enhanced 40 times and the signal-to-noise ratio is improved by 43 times at maximum. Power of pump is taken into consideration to analyze its impact on signal. A limit of detection (3σ criterion standard) of 83 ppm for CO2 is calculated for the multi-pass ring-cavity. The limit of detection of 14 ppm for CH4 is also estimated by the theoretical ratio of cross section values of CO2 and CH4. When power of excitation is low, high level of signal of multi-species gases is acquired with fine detection sensitivity through ring cavity.

Modeling of Schottky diode and optimal matching circuit design for low power RF energy harvesting

This work designs and implements a single-stage rectifier-based RF energy harvesting device. This device integrates a receiving antenna and a rectifying circuit to convert ambient electromagnetic energy into useful DC power efficiently. The rectenna is carefully engineered with an optimal matching circuit, achieving high efficiency with a return loss of less than −10 dB. The design uses a practical model of the Schottky diode, where both RF and DC characteristics are derived through extensive experimental measurements. The results from both experiments and simulations confirm the effectiveness of the design, showing its proficiency in efficient RF energy harvesting under low-power conditions. The antenna produced operates in the wifi band with a gain close to 4 dBi and a bandwidth of 100 MHz. With a load resistance of 1600 Ω, the proposed device achieves an impressive RF-to-DC conversion efficiency of approximately 52% at a low incident power of −5 dBm. These findings highlight the potential and reliability of rectenna systems for practical and efficient RF energy harvesting applications. The study significantly contributes to our understanding of rectenna-based energy harvesting, providing valuable insights for future design considerations and applications in low-power RF systems.

Radiative‐Recombination Thermodynamics in Boron‐Doped Diamond

AbstractBoron‐doped diamond is a wide‐bandgap semiconductor with excellent semiconductor properties, which is widely utilized in various applications. Till now, the thermodynamic rules governing the carrier transitions in this material have not been fully understood. In this research, the different luminescence behaviors of boron‐doped diamond under 193 nm pulse laser with high‐ and low‐ power density excitation are analyzed. Under high‐power density excitation (@≈63 kW cm−2), the emission intensity of excitons is nearly ten times higher than that of defect luminescence. Conversely, under low‐power density excitation (@≈1.4 kW cm−2, different emission peaks exhibit similar intensities, indicating a competitive relationship among them. Based on experimental and theoretical analyses, the difference is attributed to the thermodynamic distribution of carriers at varying excitation powers. Specifically, high excitation power brings an independent behavior of each emission peak, and the exciton emission is described by a phonon‐assisted radiation model; different from that, the competition among different emission centers under the condition of low excitation power cannot be neglected, and now the thermodynamic evolution of each emission peak is described by a carrier trapping‐dissociation model.

High-efficiency low-power 13C-15N cross polarization in MAS NMR

Biomolecular solid-state magic angle spinning (MAS) NMR spectroscopy frequently relies on selective 13C-15N magnetization transfers, for various kinds of correlation experiments. Introduced in 1998, spectrally induced filtering in combination with cross polarization (SPECIFIC-CP) is a selective heteronuclear magnetization transfer experiment widely used for biological applications. At MAS frequencies below 20 kHz, commonly used for 13C-detected MAS NMR experiments, SPECIFIC-CP transfer between amide 15N and 13Cα atoms (NCA) is typically performed with radiofrequency (rf) fields set higher than the MAS frequency for both 13C and 15N channels, and high-power 1H decoupling rf field is simultaneously applied. Here, we experimentally explore a broad range of NCA zero-quantum (ZQ) SPECIFIC-CP matching conditions at the MAS frequency of 14 kHz and compare the best high- and low-power matching conditions with respect to selectivity, robustness, and sensitivity at lower 1H decoupling rf fields. We show that low-power NCA SPECIFIC-CP matching condition gives rise to 20% sensitivity enhancement compared to high-power conditions, in 2D NCA spectra of microcrystalline assemblies of HIV-1 CACTD-SP1 protein with inositol hexakis-phosphate (IP6).

Effects of recalling episodes of influencing attempts on cognition in Japan

This study examined the power-cognition relationships in Japan, considering the differences related to interpersonal influence from Western cultures. Participants were instructed to recall episodes of influencing others (high-power condition) or being influenced by others (low-power condition), think about managing a group as a leader, or recall the summary of a drama or movie as a control condition. In Study 1, participants in the high-power condition reported a higher sense of power than those in the low-power condition. Participants in the control condition of Study 2 rated their sense of power the least among the four experimental conditions. However, there were no differences in innovativeness, positive affection, and the Behavioral Approach System between the high-power and control conditions. Many of the results of Bayesian factors supported the null hypotheses. These results did not support the power-cognition relationships. Considering that the Japanese are globally considered to be less assertive, these results suggest a low susceptibility to the activation of a sense of power and the possibility of a weakness in the frame of power in Japanese interpersonal relationships.