Low Operation Research Articles

Amphiphilic Interface-Mediated Ion Doping for High Performance Organic Electrochemical Transistors with Hydrophobic Polymers.

An organic electrochemical transistor (OECT) is one of the promising devices for bioelectronics due to its high transconductance, encompassing low operation voltage, and good compatibility with aqueous conditions. Despite these advantages, the challenge of balancing ion penetration and electron transport remains a significant issue in OECTs. Herein, we present an amphiphilic interface modification strategy to successfully prepare OECTs in aqueous conditions based on a high-mobility hydrophobic polypyrrole derivative. An amphiphilic interface mixed with an amphiphilic polymer and the active layer markedly promotes ion penetration and results in a significant improvement in performance, with the switch time reduced from several seconds to nearly 100 ms and the transconductance increased by an order of magnitude. The high-performance OECTs fabricated by this method show promising applications in high-performance neuromorphic devices and ECG recording in advancing the field of electrochemical transistors.

Abstract ladder operators for non self-adjoint Hamiltonians, with applications

Ladder operators are useful, if not essential, in the analysis of some given physical system since they can be used to find easily eigenvalues and eigenvectors of its Hamiltonian. In this paper we extend our previous results on abstract ladder operators considering in many details what happens if the Hamiltonian of the system is not self-adjoint. Among other results, we give an existence criterion for coherent states constructed as eigenstates of our lowering operators. In the second part of the paper we discuss two different examples of our framework: pseudo-quons and a deformed generalized Heisenberg algebra. Incidentally, and interestingly enough, we show that pseudo-quons can be used to diagonalize an oscillator-like Hamiltonian written in terms of (non self-adjoint) position and momentum operators which obey a deformed commutation rule of the kind often considered in minimal length quantum mechanics.

The comprehensive study of hybrid dielectric layer adopted organic thin film transistors for low voltage operation

Organic electronics hold immense promise due to their flexibility, low-cost processing, and diverse applications. Despite tremendous progress, low-voltage operation has remained a significant hurdle, impacting device efficiency. Our investigation introduces a new class of low voltage driven pentacene transistors, featuring hybrid gate insulators composed of polymer buffer layer and oxygen-plasma reacted high-k metal oxides viz. AlOx, TiOx, and TaOx. We demonstrate that a combination of titanium dioxide (TiOx) as the high-k dielectric layer and poly vinyl phenol (PVP) as a buffer layer in organic thin-film transistors (OTFTs) achieves exceptional performance compared to aluminium oxide (AlOx) and tantalum oxide (TaOx). This innovative approach yields the notable field-effect mobility (1.5 cm2/Vs) and a commendable on/off ratio (3.4 × 104), surpassing devices fabricated with other high-k oxides. The success lies in the PVP’s ability to smooth surfaces and reduce interface defects, while TiOx’s superior dielectric constant fosters stronger gate control. These findings pave the way for the development of next-generation organic devices with significantly lower operating voltages, opening doors for energy-efficient and flexible electronics.

Some algebras and logics from quasiorder-generated covering-based approximation spaces

In A. Kumar, & M. Banerjee [(2012). Definable and rough sets in covering-based approximation spaces. In T. Li. (eds.), Rough sets and knowledge technology (pp. 488–495). Springer-Verlag], A. Kumar, & M. Banerjee [(2015). Algebras of definable and rough sets in quasi order-based approximation spaces. Fundamenta Informaticae, 141(1), 37–55], authors proposed a pair of lower and upper approximation operators based on granules generated by quasiorders. This work is an extension of algebraic results presented therein. A characterisation has been presented for those quasiorder-generated covering-based approximation spaces whose corresponding collections of definable and rough sets form Stone algebras. The notion of rough lattice was proposed in A. Kumar, & M. Banerjee [(2015). Algebras of definable and rough sets in quasi order-based approximation spaces. Fundamenta Informaticae, 141(1), 37–55], A. Kumar [(2020). A Study of Algebras and Logics of Rough Sets Based on Classical and Generalized Approximation Spaces. In Transactions on Rough Sets XXII, LNCS (Vol. 12485, pp. 123–251). Springer]. Some special rough lattices are introduced in this work, viz. rough Stone algebra, ∼ 1 -complemented and ∼ 2 -complemented rough lattices. Representations of these algebras in terms of rough sets are obtained. Moreover, logics for these algebras are shown to be sound and complete with respect to rough set semantics.

An Almost Deterministic Cooling by Measurements

AbstractNondeterministic measurement‐based techniques are efficient in reshaping the population distribution of a quantum system but suffer from a limited success probability of holding the system in the target state. To save the experimental cost, a two‐step protocol is proposed to cool a resonator down to the ground state with a near‐unit probability by exploiting the state‐engineering mechanisms of both conditional and unconditional measurements on an ancillary qubit. In the first step, the unconditional measurements on the ancillary qubit are applied to reshape the target resonator from a thermal state to a reserved Fock state. The measurement sequence can be efficiently optimized by reinforcement learning for maximum fidelity. In the second step, the population on the reserved state can be faithfully transferred in a stepwise way to the resonator's ground state with a near‐unit fidelity by the conditional measurements on the qubit. Properly designing the projection operator and the measurement interval enables the Kraus operator to act as a lowering operator for neighboring Fock states. Through dozens of measurements in all, the initial thermal average population of the resonator can be reduced by five orders in magnitude with a success probability of over 95%.

A Low-carbon Dispatching Method for Cascade Hydropower via HVDC Flexible Delivery

Abstract As a country rich in hydropower resources, the transmission of Southwest hydropower through HVDC system can achieve a large range of optimal allocation of resources, but the traditional HVDC transmission plan is often operated in high and low binary value, which is difficult to give full play to the flexibility of HVDC transmission, and increase the carbon emission and operation cost of the power system. In order to fully explore the flexibility of HVDC transmission mode to reduce system carbon emissions, this paper builds a mixed integer programming model based on the scenario of hydropower being sent to the receiving system through the HVDC system, taking into account such factors as low operating costs and carbon dioxide emissions of thermal power units at the receiving end, overload capacity of the HVDC system, and reactive power compensation cost of the HVDC system. A low carbon scheduling method for cascade hydropower HVDC flexible delivery system is proposed. Finally, taking the cross-regional transmission system of cascade hydropower station as an example, the model proposed in this paper is compared with the high-low binary transmission of traditional HVDC system. The results show that the dispatch mode proposed in this paper and the flexible operation of the HVDC system can promote the consumption of new energy, reduce the CO2 emissions of the system and achieve the dispatch goal of both low carbon and economic operation.

Renewable energy sharing based on the effect of energy supply from energy transportation and storage side on building load demand

Abstract To lower environmental-based operation costs, many literatures studied the relationship between the energy generation side (EGS) and building load (BL) demand side based on solar-based integrated energy systems (SIESs), without directly considering the effect of energy from energy transportation and storage side (ETSS) on BL demand, which may result in waste of solar energy extracted. To enhance energy utilization, this study proposed an analysis method that renewable energy source shares among different buildings was investigated based on the supply relationship between energy from the ETSS side and BL demand side. ETSS included an electric boiler/chiller (EB/C), double-effect absorption heat pump (AHP) and tank. According to the energy sources from ETSS and building loads for a hotel, a residence and a hospital on a heating/cooling day. The proposed analysis method was used to develop the potential of available renewable energy through energy sharing from the perspective of the energy consumption differences of the three buildings. The results presented that the potential of renewable energy utilization was further developed by reasonably operating the use and storage of energy sources from ETSS based on the optimization between energy sources from EGS and building loads. Energy source shares among different buildings with different energy consumption characteristics enhanced energy efficiency according to reasonably change the useable time of energy sources from tanks. When a building required a large number of energy sources, the buildings with low energy consumption directly shared renewable energy without considering the use of energy storage. This study can provide a reference for optimizing the design of integrated energy system (IES)-based architecture with different building loads.

The effects of tourniquet use in elbow surgery: a retrospective analysis

BackgroundPneumatic tourniquets are frequently employed in extremity surgeries, aiming to enhance intraoperative visibility and minimize blood loss. While their benefits and drawbacks have been extensively studied in lower limb operations, their impact on upper limb procedures, particularly elbow surgery, remains poorly understood. This study investigates the advantages and risks associated with pneumatic tourniquet utilization in elbow surgery. MethodsA retrospective analysis was conducted on 183 patients who underwent elbow surgery for fractures between January 2019 and September 2023. Patients were categorized into two groups: those who underwent surgery with a tourniquet (WT) and those without a tourniquet (NT). Subgroup analyses were performed based on fracture complexity. Data collected included patient characteristics, tourniquet usage, surgical duration, pre- and postoperative hemoglobin levels, C-reactive protein levels, pain assessments, opioid administration, hospital stay duration, follow-up, complications, and revisions. Statistical analyses were used to identify significant differences and correlations. ResultsThe use of a tourniquet in elbow surgery yielded several notable outcomes. Patients in the WT group experienced significantly shorter surgical durations and hospital stays. Hemoglobin drop was lower in the WT group, indicating reduced blood loss. However, there were no significant differences in postoperative pain, opioid consumption, or complications between the WT and NT groups. Subgroup analysis revealed that the recorded differences, particularly shorter surgical durations, were more pronounced in complex fractures. ConclusionsThis study shows promising results in the use of pneumatic tourniquets in elbow surgery in terms of enhanced efficiency, reduced blood loss, and overall safety, without compromising patient outcomes. However, the potential influence of perioperative decision-making on tourniquet usage underscores the need for further research to elucidate its role and optimize its application, especially in complex elbow fractures.

A novel boost power converter suitable for bearingless switched reluctance motor with wider rotor teeth

Abstract Aiming at the problem that the excitation current build-up speed of the bearingless switched reluctance motor with wider rotor teeth (BSRMWR) is too slow during commutation, this paper proposes a simple structured boost power converter. When the motor is commutation, it uses the winding demagnetization energy to quickly establish the excitation current for the latter phase winding and realizes the low torque ripple operation of the motor on the basis of ensuring the stable levitation of the motor. The topology and working status of the novel power converter are analyzed. On this basis, a 12/8 pole single-winding BSRMWR driving system based on the novel boost power converter is constructed. Through Matlab/Simulink simulation, the feasibility and effectiveness of the novel power converter are verified.

Performance of tube heat pipe solar collector with phase change material for seawater desalination system

Abstract Unlimited seawater resources resulted for utilization of desalination systems using seawater treatment process emerges as a promising technology for addressing the continually escalating need for freshwater. At present, the most notable desalination processes that are reverse osmosis, membrane distillation, multistage desalination, multiple-effect distillation, and electrodialysis, require energy generated by fossil fuels to obtain fresh water. Among the noteworthy sources of renewable energy, solar energy stands out with its manifold applications. The use of solar energy has strong advantages, such as a low maintenance and operation costs. In this study, a novel solar desalination system is introduced, which integrates tube heat pipe solar collector (THP-SC) equipped with phase change material (PCM). The aim of this research is to evaluate the performance of THP-SC equipped with PCM and without PCM. The feedwater sample used is water. Parameters measured for 24 hours were temperature, solar radiation, ambient air temperature, relative humidity, and wind speed. The greatest recorded solar radiation at noon (11.52 a.m.) is 900 W/m2 while the maximum recorded ambient temperature at 12.45 p.m. is 35.2°C. The experimental study showed that from morning to afternoon (06.00-15.00), the temperature of the evaporator section of the heat pipe on the THP-SC without PCM (46.70-56.21°C) was higher than the temperature of the evaporator section of the heat pipe on the THP-SC with PCM (33.18-44.43°C). This is because solar radiation will heat the PCM first before heating the heat pipe. PCM can store heat energy and release it at night. This can be seen from the water temperature in THP-SC with PCM (28.39-36.03) which is higher than the water temperature in THP-SC without PCM (27.17-34.01) at night, but the temperature difference is not significant. This can be caused by the large amount of heat lost to the environment in THP-SC with PCM, it is best to coat the heat pipe tube with insulation and create a vacuum to reduce heat loss.

Novel E-Shaped Waveguide Relativistic Extended Interaction Oscillator With Low Magnetic Field Operation

Novel E-Shaped Waveguide Relativistic Extended Interaction Oscillator With Low Magnetic Field Operation

Highly-improved formaldehyde gas sensitivity, selectivity and stability of Ce-doped In2O3 sensors at low temperature

Formaldehyde, a prevalent indoor toxic gas, can quickly harm individuals when the concentration reaches 20 ppm. Therefore, the development of gas sensors with high selectivity and sensitivity to ppm formaldehyde is highly promising. Ce-doped In2O3 microtubes are prepared through environmentally friendly one-step hydrothermal method. After the characterization of microstructure, morphology and composition of Ce-doped In2O3 microtubes, the gas-sensing performance is investigated in detail. All results indicate that Ce-doping results in lattice defects and grain refinement, leading to the higher specific surface area and more oxygen vacancies. Ce-doping greatly improves the formaldehyde gas-sensing performance of Ce-doped In2O3 sensors. 5Ce–In2O3 sensor the highest response value (563.07) to 10 ppm formaldehyde at the lower operating temperature of 210 °C, which is 4.59 times of In2O3 sensor at 230 °C. Moreover, Ce-doped In2O3 sensors exhibit the excellent selectivity, long-term stability and humidity stability. The overall-improved formaldehyde gas-sensing behavior of Ce-doped In2O3 sensors is attributed to more oxygen vacancies, larger specific surface area, reduced bandgap, Ce3+→Ce4+ transition and Ce4+ donor doping due to Ce-doping.

Interfacial metal ions rearrangement of LaFe2O4-WO3 heterostructure for developing ceramic fuel cells cathode

The development of high-performance electrochemical energy devices requires efficient oxygen redox reaction (ORR) electrocatalysts. In particular, ceramic fuel cells suffer from insufficient oxygen reduction reaction (ORR) of the cathode material at low operating temperatures. Here we report a series of three-dimensions bulk LaFe2O4-WO3 heterostructure composites synthesized by a citric acid complexing method for a solid oxide fuel cell's (SOFC) cathode material to work at lower operating temperature at 450-550 ° C. In various contents of LaFe2O4 and WO3, the 7LaFe2O4–3WO3 cathode exhibits very small area-specific-resistance (ASR) of 0.24 Ω cm2 and admirable peak power density of 625 mW-cm−2 when operating at 550 °C using Ni0.80Co0.15Al0.05LiO2-δ (NCAL) anode and Sm0.20Ce0.80O2 (SDC) electrolyte, respectively. Different characterizations such as HR-TEM, XPS, Raman, spectroscopy and calculation density functional theory (DFT) methods has been used to identifying the main reason for the improved electrochemical performance through the interface between LaFe2O4 and WO3 heterostructure in comparison of individual LaFe2O4 and WO3 structures. We have found that the LaFe2O4-WO3 heterostructure shows superficial oxygen ions release and electronic mobility which increase the overall active-sites for the enhanced ORR functionality. This aromatic approach can lead a step forward to develop desirable electrocatalysts by crosslinked interfacial properties using semiconductor-heterostructure materials for advanced energy devices.

Ultra-selective hydrogen sensors based on CuO - ZnO hetero-structures grown by surface conversion

Synergistic effects of mixed oxides have the potential to improve sensing performances of environmental, domestic and industrial monitoring devices. However, mixed oxides often come in the form of separate particles and are thus addressed separately by the environment, instead of capitalizing on the interface between the metal oxides. This paper describes a new core@shell gas sensing material of tetrapodal zinc oxide with a surface coating of crystalline copper oxide(t-ZnO@CuO). The special surface conversion strategy yields a unique, self-assembled and pinhole-free coating of CuO nanoplatelets. The morphologies, structural, chemical and gas sensing properties of the heterostructure were investigated. To evaluate the sensing properties of the heterostructure, t-ZnO@CuO was fabricated as nanosensors, consisting of one core-shell rod of CuO-coated crystalline ZnO. The single core@shell rod showed high selectivity towards hydrogen already at comparatively low operation temperatures of 150 °C. Computational calculations based on the density functional theory (DFT) have been carried out to understand the interaction of the H2 gas molecule with the surface of the CuO nanostructures. The surface conversion was done wet chemically and is a novel method for generating heterostructures that can be potentially transferred to heterojunctions with unique properties for chemosensors.

Parameter fine tuning on CRDI engine operated with blends of grape biodiesel and diesel

This study investigates the feasibility of using grape biodiesel from the wine industry as a sustainable and cost-effective alternative to traditional fuels. The research focuses on optimizing key parameters like blend ratio, injection timing, injection pressure, engine load, and exhaust gas recirculation in a Common Rail Direct Injection engine to achieve low emissions without compromising performance. Due to grape biodiesel's higher viscosity, different energy content, and varying ignition delays compared to diesel, precise adjustments are essential for complete combustion and reduced emissions. This study uses response surface methodology and a Central Composite Design matrix to find the best values for a number of parameters in modern CRDI engines that use advanced electronic control units. Through fifty input combinations, the study aims to minimize specific fuel consumption, hydrocarbons, nitrogen oxides, and carbon monoxide while maximising brake thermal efficiency, brake mean effective pressure, and mechanical efficiency. The optimal configuration includes a fuel injection timing of 6° bTDC, an engine load of 82 %, 6.7 % EGR, 1000 bar injection pressure, and a 33 % grape biodiesel blend. These optimum input conditions yielded outputs of 3.55 bar BMEP, 31.85 % BTE, 64 % mechanical efficiency, 0.278 kg/kWh SFC, 0.127 % CO, 357 ppm NOx, and 8 ppm of HC. These adjustments ensure low emissions and efficient engine operation, highlighting grape biodiesel's potential as a viable alternative fuel.

Direct electron transfer mediated electrochemical activation of persulfates by reticulated vitreous carbon (RVC) cathode

The electrochemical activation of peroxymonosulfate (PMS) and peroxydisulfate (PDS) for pollutant degradation has gained increasing attention. In this work, reticulated vitreous carbon (RVC) electrodes were prepared at a low cost and investigated for the cathodic activation of PMS/PDS for Acid Orange 7 degradation. The RVC was characterized by SEM, TGA, XRD, Raman spectroscopy, XPS, EIS, and compression test. The superior activity outperformed previous reports in terms of low current density operation (1–10 mA/cm2), high degradation rates (0.13–0.49 min−1), low energy consumption (0.03–0.23 kWh/m3/order) without involvement of catalysts. The process was optimized for current density, PMS dosage, pollutant concentration, pH, water matrix, and supporting electrolyte. Under the optimal current density (3 mA/cm2), the addition of 0.5 mM of PMS boosted the degradation rate by 9.6 times to 0.4470 min−1 and reduced the electrical energy consumption by 90.1 % to 0.0243 kWh/m3/order in 50 mM of Na2SO4. Moreover, up to 117 mg/L of H2O2 was produced in 1 hour by the reduction of oxygen, with current efficiencies between 78–24 %. The process showed little deterioration in 10 cycles, worked for a variety of pollutants, and was not affected by the water matrix. The H-cell experiments confirmed that 90 % degradation took place on the cathode. Scavenging experiments and electrochemical tests suggested that the transitional state of PMS* and O2•− mediated the direct electron transfer mechanism for AO7 degradation. Eighteen degradation products were identified by HPLC-MS and categorized into 4 degradation pathways. Finally, their toxicity was assessed by the ECOSAR programme.

Low noise operation of an all polarization-maintaining figure-9 Er:fiber laser with near-zero cavity dispersion

We demonstrate the low noise operation of a figure-9 1.5-μm Er:fiber laser constructed by all polarization-maintaining (PM) fiber and fiber components. Starting from the original rate equations and nonlinear Schrödinger equation, the cavity roundtrip evolution toward stable mode locking state is present. The radio frequency spectrum shows a 94.6-MHz fundamental repetition rate with up to 100 dB high signal-to-noise ratio. The net dispersion is tailored to near zero by incorporating and optimizing the length of PM dispersion-compensating fiber in the cavity. As a result, an integrated root-mean-square relative intensity noise of 0.0026 % [1 Hz, 1 MHz] and 10.8-fs timing jitter [100 Hz, 1 MHz] at the fundamental repetition rate are measured. We also lock the fundamental repetition frequency to a stable radio frequency reference and an in-loop relative stability of 2.1 × 10−12 at 1-s gate time is obtained.

Silver nanoparticle functionalized heterojunction NiO/SnO2 nanotubes for comprehensive sensitization of acetone sensor

Acetone detection with a good sensitivity and a low operating temperature is crucial owing to the serious harm that acetone can cause to the environment and humans and its importance as a marker of diabetes in human exhalation. One-dimensional (1D) semiconductor metal oxides with easily accessible active sites are potential candidates for use in gas sensors; however, the facile synthesis of 1D nanotubes (NTs) remains a challenge. Herein, Ag–NiO/SnO2 NTs are synthesized via an electrospinning process, followed by spin-coating permeation and subsequent annealing and chemical reduction; furthermore, the gas-sensing properties of the Ag–NiO/SnO2 NTs are investigated. The Ag–NiO/SnO2 NT-based sensor exhibits a rapid response to acetone (12 s) with excellent sensitivity and selectivity at a low operating temperature (190 °C). The lower acetone detection limit of the Ag–NiO/SnO2 NT-based sensor is 50 ppb. The 1D porous NTs efficiently promote gas diffusion during reversible resistance signal cycling and provide numerous active sites. Furthermore, the conjunction of NiO nanograins with SnO2 nanograins forms a heterogeneous construction, enhancing the gas sensitivity of the sensing layers. In addition, Ag nanoparticles homogeneously incorporated onto the surface of the 1D NTs enhance substantially the acetone detection capability based on noble-metal sensitization.

Design and analysis of a novel resistorless frequency selective network for low voltage operation

Design and analysis of a novel resistorless frequency selective network for low voltage operation

Carbon Dioxide Capture: Current Status and Future Prospects

The surge in greenhouse gas emissions, predominantly in the form of carbon dioxide (CO2) spurred by the Industrial Revolution, has surpassed the critical threshold of 400 ppm, fueling global warming, ocean acidification, and climate change. To mitigate the adverse effects of these emissions and limit the global temperature rise to below 2 °C, the ambitious target of achieving net zero emissions by 2050 was established in the Paris Agreement. Current state-of-the-art technologies, such as amine scrubbing, remain problematic owing to their high energy requirements, susceptibility to corrosion, and other operational challenges. Owing to the lack of suitable technologies coupled with escalating energy demand, there is still a significant amount of carbon dioxide being released into the atmosphere. Accordingly, there is an urgent need for the development of alternative technologies that offer high efficiency, low energy consumption, cost-effective installation, and operation. In this review, we delve into the emerging technologies poised to address these challenges, evaluating their maturity levels in comparison to existing commercially available solutions. Furthermore, we provide a brief overview of ongoing efforts aimed at commercializing these innovative technologies.