Additional Energy Consumption Research Articles

Experimental study on the operating characteristic of the desiccant cooling systems with the potential of condensing heat recovery

The requirement for extra regeneration heat is a significant issue limiting the energy efficiency of desiccant cooling systems. To avoid the additional energy consumption, this study analyses two systems that use condensing heat to regenerate the desiccant. The experiments for the heat pump-assisted type are executed at different indoor load profiles. A comparative experiment is carried out on a water loop-assisted type. Experimental results show that the heat pump-assisted type obtains a maximum regeneration temperature of 40.4 °C and a minimum supply air humidity ratio of 3.5 g/kg DA at the outdoor temperature below 26 °C. However, the thermal imbalance problem leads to uncontrollable indoor temperatures under 50 W/m2 load conditions. The proposed operation mode automatic switching control can improve indoor temperature by switching the system between dehumidification and cooling modes. Compared to the heat pump-assisted type, the water loop-assisted type has the same dehumidification capacity and a more stable indoor thermal environment control using high temperature chilled water above 14 °C and reduce the total primary cooling energy consumption by 58%. This study analyses the feasibility of recovering condensing heat from the perspective of thermal energy analysis, and expands the research on desiccant cooling systems without extra regeneration heat sources.

Explore Deep Reinforcement Learning to Energy-Efficient Data Synchronism in 5G Self-Powered Sensor Networks

Recently, the explosive data traffic growth and large-scale Internet of Things (IoT) equipment connection have brought 5G mobile communication technology many challenges. The communication delay of network services such as augmented reality, smart grid, disaster warning and emergency communication have been relieved by 5G. However, these services are still confronted with the serious challenge in energy conservation. Most of traditional optimization methods usually need complex operations and iterations to get the optimal results, which are not suitable for communication systems with high real-time performance. Based on this argument, this paper has focused on the green communication in Mobile Edge Computing (MEC)-based self-powered sensor network and proposed a novel approach called MIDS (Mobile Intelligent Data Synchronization based on deep reinforcement learning). It exploits Deep Deterministic Policy Gradient (DDPG), continuous interacting with the environment and making tryouts to evaluate the feedback from the environment to optimize future decision-making on the path selection scheme for data transmission as well as achieve the energy efficiency and energy consumption balance of mobile devices with self-powered sensors. We provide experiments to show the capability of our approach in reducing the additional energy consumption of mobile devices and the base station as well as balancing the energy consumption of mobile devices with sensor communication. The superiority of our approach for energy conservation in data synchronization is convincingly demonstrated by comparing with state-of-the-art methods in MEC-based self-powered sensor network.

Humidity grade-matched fresh air dehumidification system with adjustable treating stages

Air conditioning systems using liquid desiccants are efficient in dehumidification, but their performance can be further improved under both design and different partial load conditions. In this study, a humidity grade-matched system with adjustable treatment stages is designed based on the use of appropriate humidity sinks to handle loads. The method to determine reasonable treatment stage numbers and packing tower areas is given by optimizing the total system energy consumption and economic performance under different working conditions, based on validated numerical system performance models and device prices from the market or literature. The performance of the proposed system is compared with traditional systems in a case office building in Nanjing. The results are as follows: 1. By optimizing the total system power consumption and economic performance under different conditions, the humidity difference for one-stage and mass transfer humidity difference should be set at 3–5 and 2–3 g/kg to determine the stage number and packing tower area, respectively. 2. The proposed fresh air dehumidification system as applied to an office building without exhaust air in Nanjing reduces 16.6% and 13.5% of the seasonal energy consumption for the entire system relative to single-stage and three-stage systems, respectively. 3. When the system selectively uses exhaust air or outdoor air, 11.0% of additional seasonal energy consumption can be saved for the entire system relative to a system using only outdoor air.

Research of the dynamics of the all-wheel-drive tractor-transport machine

The study results of the dynamic and traction-energy performance of an all-wheel drive traction-transport vehicle have been presented. A diagram of a dynamic model of the transmission of an all-wheel drive traction-transport vehicle and a system for calculating the transmission dynamics in the Cauchy form has been compiled. The method makes it possible to determine the distribution of the coil fluids of the transmission elements of a traction-transport vehicle, the distribution of torque moments, and the distribution of additional traction forces on the wheels per hour. The method allows you to determine the optimal transmission parameters, differential design, and transmission numbers to improve the traction and fuel-economic performance of the machine. It has been established that the speed of the front wheels of a traction and transport vehicle is 1.29 rad/s, 1.27 rad/s, and the speed of the rear wheels is 1.24 rad/s, 1.25 rad/s, which should be carried out until kinematic instability and additional energy consumption. The torque values of the front drive wheels are 6972 N m, and the rear drive wheels are 4622 N m. The additional traction forces on the car's front wheels are 5478 N after the car's acceleration is completed, and on the rear wheels, they are 347 3 N. To verify the adequacy of the method for assessing the dynamics of an all-wheel drive transmission, Wheeled traction, and transport vehicles have been developed to simulate the dynamics and energy systems of mobile vehicles—experimental research of the machine on the butt of an all-wheel drive wheeled tractor with an articulated frame. The difference between the values of the heel fluids of the wheel wraps, theoretically and experimentally, is 2%, which indicates a significant loss of the heel fluids by the wheel dynamics sensors. A comprehensive method for assessing the transmission dynamics of an all-wheel drive traction and transport vehicle must be considered adequate. The robotic method can be used to assess the dynamics of wheeled vehicles in motor vehicles. Keywords: cutting speed, torque, traction force, transmission, traction, and transport vehicle.

Innovative Solution for Reducing Yarns Hairiness on Ring Spinning Machines

ABSTRACT Yarn’s hairiness represents a continuous challenge for spinning technologies. To keep this aspect under control, an almost perfect combination between the construction and performance of the machines, the control of the technological processes through appropriate settings, and the experience of the producers are required. As a consequence, the researchers were preoccupied to adapt or modify the ring frame to produce yarns with a lower degree of hairiness. Spinning triangles as a very demanding area exert a crucial impact both on the distribution of fiber tension and their spatial location in the staple yarn structure. Our study encompasses yarn hairiness reduction employing a device composed of two bars. Various combinations of spindle speeds and contact angles between yarns and bars were tested to examine their effects on yarn hairiness. The study was completed with the optimization of technological parameters using a central, composite, rotating program with two independent variables (spindle speed and contact angle) to establish mathematical models and optimize technological parameters for the reduction of hairiness. The effectiveness and efficiency of this device consist of the easy execution and installation on the existing machines in spinning mills without any constructive adjustments and additional energy consumption.

The Intel neuromorphic DNS challenge

A critical enabler for progress in neuromorphic computing research is the ability to transparently evaluate different neuromorphic solutions on important tasks and to compare them to state-of-the-art conventional solutions. The Intel Neuromorphic Deep Noise Suppression Challenge (Intel N-DNS Challenge), inspired by the Microsoft DNS Challenge, tackles a ubiquitous and commercially relevant task: real-time audio denoising. Audio denoising is likely to reap the benefits of neuromorphic computing due to its low-bandwidth, temporal nature and its relevance for low-power devices. The Intel N-DNS Challenge consists of two tracks: a simulation-based algorithmic track to encourage algorithmic innovation, and a neuromorphic hardware (Loihi 2) track to rigorously evaluate solutions. For both tracks, we specify an evaluation methodology based on energy, latency, and resource consumption in addition to output audio quality. We make the Intel N-DNS Challenge dataset scripts and evaluation code freely accessible, encourage community participation with monetary prizes, and release a neuromorphic baseline solution which shows promising audio quality, high power efficiency, and low resource consumption when compared to Microsoft NsNet2 and a proprietary Intel denoising model used in production. We hope the Intel N-DNS Challenge will hasten innovation in neuromorphic algorithms research, especially in the area of training tools and methods for real-time signal processing. We expect the winners of the challenge will demonstrate that for problems like audio denoising, significant gains in power and resources can be realized on neuromorphic devices available today compared to conventional state-of-the-art solutions.

Comparison of forming processes for micro textured cups

Friction losses are present in all kinds of technical systems. This is always associated with additional energy consumption, which can be partly avoided as it arises. Energy savings can be achieved by a wide range of approaches. The application of friction reducing coatings on bodies in relative motion is widespread. The coating of parts is however only suitable to a limited extent for the production in large batches. Therefore, research approaches consider alternative methods to achieve friction reductions. A promising approach is the integration of miniaturized pockets on the surface of the component. In lubricated contacts, the lubricant can then accumulate in these indentations. The relative motion between two bodies thus builds up a hydrodynamic pressure and consequently reduces friction. Forming technology is suitable for the efficient production of metallic components in large quantities. The aim of this study is therefore to identify challenges in the integration of micro coining in established forming processes. Two processes from sheet metal forming and bulk metal forming are investigated. In a combined experimental and numerical approach, process-specific challenges are derived regarding the texturing process and the numerical process modelling for combined micro coining. The analysis is carried out on a cup geometry, as used in the automotive sector as tappets in the valve train. The case hardening steel 16MnCr5 (1.7131) is used as workpiece material.

Research directions for reducing the resistance force to the movement of a wheeled power vehicle

The article discusses the efficiency of the use of energy means largely depends on the traction properties developed by them, which directly affects the realized traction force on the hook. Studies have established that the tangential thrust force realized by the energy means is spent on overcoming the forces of resistance to movement and overcoming the forces of resistance of the agricultural machine. In turn, the resistance strength of an agricultural machine largely depends on the physical and mechanical properties of the soil, the width of the grip and the speed of movement, especially on clay and heavy loamy soil types. It should be noted that this type of soil has a significant impact on the strength of resistance to movement, which is due to the fact that at the same time there is an additional force associated with overcoming the viscosity forces that arise between the soil particles when they are separated from each other. In addition, when the soil adheres to the propellers of the energy vehicle, there is an additional energy consumption for the promotion of additional flywheel masses with an increase in the mass of the propeller. Research and industrial observations have established that one of the ways to reduce the force of resistance to movement on clay and heavy loamy soils is the timely cleaning of wheel movers from the soil adhering to them. In the presented article, the issue of reducing the force of resistance to movement due to purification (purification) of the tire tread of the wheel mover is considered.

Energy-efficient fresh air system with pressure-independent dampers for nearly zero energy buildings

Fresh air volume control is of great significance in reducing energy consumption in nearly zero energy buildings. Previous studies have shown that the operating fresh air volume often deviates significantly from the design value, resulting in unnecessary energy consumption. To overcome this problem, this study proposes an energy efficiency fresh air system for NEBs by using pressure-independent dampers to balance system resistance and control the operating fresh air volume accurately. A typical fresh air system used in a typical NZEB was tested both in laboratory and on site for a whole heating season. Based on the test data, the energy consumption model of the proposed fresh air system was established and validated. The energy performance of the proposed system was analyzed comprehensively. Results show that using the pressure-independent damper in the fresh air system to control the fresh air flow rate can significantly reduce the fresh air load by 39.2%, 49.4%, 52.3% and 45.5% in Harbin, Beijing, Shanghai and Guangzhou, respectively; The annual energy saving rates in these cities are approximately 29.3%, 28.7%, 27.0% and 19.1%, respectively. These energy saving rates are smaller than the corresponding fresh air load reductions due to the additional energy consumption caused by the pressure-independent damper; Furthermore, replacing the pressure-independent damper with an ideal variable speed ventilator for fresh air flow rate control can further increase the energy saving rate by 12%∼16%. This study identifies the energy saving potential of fresh air systems and contributes to achieving sustainable development in nearly zero energy buildings.

Proof of Evaluation-based energy and delay aware computation offloading for Digital Twin Edge Network

The increasing availability of Internet of Things (IoT) applications has led to the development of new technologies. Specifically, the deployment of edge servers close to IoT devices has strengthened the edge computing paradigm. With the collaboration of Mobile Edge Computing (MEC) and cloud computing, delay-sensitive and computation-intensive tasks can be offloaded to the edge/cloud servers to improve system performance in terms of the delay and energy consumption of IoT devices. However, there is a need to schedule the computation tasks for an efficient management. More importantly, the task scheduling strategy can face data tampering attacks to deliberately modify, destroy or manipulate the decisions. To solve the above problems, in this paper, we newly propose to integrate digital twin and blockchain into the edge networks. However, it is unclear (i) how energy and delay-aware computation should be combined, and (ii) which mining computations should be executed for a secure task scheduling. The state-of-the-art focuses on task scheduling and blockchain mining, separately. Therefore, we propose a novel blockchain-based digital twin-edge network architecture where our proposed algorithm solves these two challenges at the same execution. We design a three-layer system architecture, composed of physical entity layer, digital twin edge layer and blockchain layer. In the physical entity layer, we formulate an energy and delay-aware task scheduling problem. In the digital twin edge layer, we propose a novel Proof of Evaluation (PoE)-based secure energy and delay-aware task scheduling algorithm where optimization is executed by the genetic algorithm implementation of Warehouse Location Problem (WLP). In the blockchain layer, the best-found solutions are shared with the topology in a blockchain. Here, each block includes the hash of the previous block, a genetic algorithm-based solution, nonce value, and a hash of whole blocks in the blockchain. Thus, we aim to execute the computation tasks with an acceptable delay in an energy-efficient manner and prevent data tampering attacks against the optimal computation decisions. We validate the outcomes of our PoE-based secure digital twin-edge network model with extensive evaluations. Since the proposed model distributes the task not only to the local device but also to the MEC and cloud server for delay awareness, it reduces the delay but consumes more energy. Nevertheless, the additional energy consumption can be neglected against the delay reduction. The proposed scheme is also more scalable to compare with the conventional solution. The numerical results clearly show that the proposed model provides energy and delay awareness, maintaining both data integrity and trustworthiness at the same execution of algorithm.

Numerical investigation of tubeside maldistribution in shell-and-tube heat exchangers

Shell-and-tube heat exchangers (STHE) are widely used in the process and energy industry. Maldistribution and the often resulting fouling in these STHE cause additional energy consumption and lower production throughput. Increased average wall shear stress, compared to that of the maldistributed case inside the tubes is expected to mitigate fouling. This can be achieved by a uniform distribution into the tubes. Field and laboratory data suggest that common crude oil fouling is profoundly mitigated above 10 Pa and is significantly reduced above a wall shear stress of 15 Pa [1]. Many STHE already have lower design shear stresses than those mentioned. Therefore, if maldistribution takes place, tubes with less flow velocity will have even more fouling. To investigate tubeside flow maldistribution, a parametric STHE model is studied with computational fluid dynamics (CFD). At first, a comparison between the standard k-ϵ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\epsilon$$\\end{document}-model and the new standard SST-model is performed to check if SST could provide improved simulation results. Afterward, a range of geometrical parameters will be investigated to find influencing quantities of maldistribution. The resulting velocity distributions are visualized and evaluated by using different statistical approaches. At least, a sensitivity analysis will be done to show how each parameter influences the tubeside flow distribution in STHE.

Nano-composite semi-flexible polyurethane foams containing montmorillonite intercalated/exfoliated in situ during the synthesis of the intermediate polyester-polyols obtained from PET wastes

Low-cost nano-composite semi-flexible polyurethane foams with improved thermal and mechanical features were obtained using a cost-saving and environmentally friendly preparation process of an intermediate composite, obtained from polyethyleneterephthalate (PET) wastes, depolymerization/chemical modification agents from renewable resources and unmodified natural montmorillonite. The process implies tailoring the polyester-polyols chemical structure/ composition and using specific catalysts, aiming to intercalate the montmorillonite layers during the synthesis reactions, while maintaining the appropriate properties of the products required for the preparation of polyurethane semi-flexible foams, thus avoiding conventional treatments of the nanofiller, involving the use of solvents, additional energy consumption by heating and stirring, as well as longer processing time. The polyester-polyols composites and the polyurethane semi-flexible foams obtained therefrom were investigated by specific analytical methods. In this regard, the foams showed an improvement of the thermal stability, and values of Young’s moduli and compression strengths about double or higher, compared to conventional semi-flexible polyurethane foams of same density. The potential applications of such foams target shock wave damping sandwich systems for marine structures.

Exergy analysis of a new spray cooling system-based PV/T and heat recovery with application in sow houses

The uncertain cooling effect and additional huge primary energy consumption caused by humidity regulation are currently the main problems of traditional environmental regulation systems in sow houses. In this study, a new spray cooling system is proposed based on PV/T and heat recovery in sow houses. Meanwhile, the mathematical models are established for its key equipment and their reliability is verified according to literature data. The results show that the maximum error is less than 14.5 % for the models. Based on the above models, the annual operation modes are determined for the new system. Specifically, its annual operation modes mainly include the cooling season, the heating season, the transitional spring and the transitional autumn. Meanwhile, the exergy loss and energy consumption are analyzed for the new system in four seasons through simulation. The results show that in the cooling and heating seasons, the exergy loss first decreases and then increases with the increase of spray power (SP) and mass flow rate of circulating water (MFRW). In the transition season, the exergy loss decreases with the increase of MFRW, while it first decreases and then increases with the increase of SP. However, the annual energy consumption increases with the increase of SP and MFRW. Aim at the minimum exergy loss of new system, its optimal control parameters are obtained in four seasons through optimization. Specifically, when the mass flow rate of supply air is the minimum ventilation rate required by sows, the optimal SP and MFRW are recommended as 40 kW and 12245 kg/h in the cooling and heating seasons, respectively. Meanwhile, they are recommended as 35 kW and 12245 kg/h in the transition season, respectively. The above research can provide guidance for the improvement of traditional spray cooling systems and the performance optimization of new system.

Joint Task Offloading and Resource Allocation for Energy-Constrained Mobile Edge Computing

We consider the problem of task offloading and resource allocation in mobile edge computing (MEC). To maintain satisfactory quality of experience (QoE) of end-users, mobile devices (MDs) may offload their tasks to edge servers based on the allocated computation (e.g., CPU/GPU cycles and storage) and wireless resources (e.g., bandwidth). However, these resources could not be effectively utilized unless an encouraging resource allocation scheme can be proposed. What's worse, task offloading incurs additional MEC energy consumption, which inevitably violate the long-term MEC energy budget. Considering these two challenges, we propose an online joint offloading and resource allocation (JORA) framework under the long-term MEC energy constraint, aiming at guaranteeing the end-users' QoE. To achieve this, we leverage Lyapunov optimization to exploit the optimality of the long-term QoE maximization problem. By constructing an energy deficit queue to guide energy consumption, the problem can be solved in a real-time manner. On this basis, we propose online JORA methods in both centralized and distributed manners. Furthermore, we prove that our proposed methods enable the achievement of the close-to-optimal performance while satisfying the long-term MEC energy constraint. In addition, we conduct extensive simulations and the results show superiority in performance over other methods.

High-Precision and Low-Power Offset Canceling Tri-State Sensing Latch in NAND Flash Memory

As the density of NAND flash memory increases, high-precision and low-power sensing latch is demanded. One promising solution for improving read precision is the offset canceling sensing latch (OCSL). The OCSL samples the trip voltage and compensates for its offset, reducing the effective trip voltage variation by 26.5%. However, the OCSL suffers from three problems due to the short-circuit between VDD and GND: 1) energy consumption of 20.7 pJ in the sense phase, 2) additional energy consumption of 78.7 pJ in the sample phase, 3) risk of data corruption in sample phase. In this study, the offset canceling tristate sensing latch (OCTSL) is proposed that achieves highprecision and low-power read operation with die area overhead of 0.015% through three key features: 1) sense phase without shortcircuit between VDD and GND by adopting tri-state sensing latch, 2) sample phase without short-circuit between VDD and GND by adding the sensing node precharge, 3) couple-down phase to enable the adoption of the tri-state sensing latch by using sensing node coupling capacitor. Compared to the OCSL, the proposed OCTSL reduces the effective trip voltage variation by 43.4%, reduces energy consumption by up to 99.1% and 78.3% in the sample and sense phases, respectively, and eliminates the risk of data corruption in the sample phase.

ANALYTICAL INVESTIGATION ON THE CONDENSATION PERFORMANCE OF VERTICAL, TILTED AND HORIZONTAL SURFACES FOR PASSIVE WATER HARVESTING

Condensate harvesting is the phenomenon of obtaining water from water vapor in the humid air condensing on a surface. The idea is a passive technique with no additional energy consumption, yet condensation performance of a surface varies with many parameters. This study analytically investigates the condensation performance of the vertical, tilted, and horizontal water harvesting systems. First, viscous effects, inertia, and gravitational forces are examined in detail to express the evolution of boundary layer in condensation film. Then the condensation performance of each surface orientation and tilt angles are documented and compared for all flow conditions. Although vertical surfaces have higher condensate harvesting performance compared to the tilted and horizontal systems, the condensation rate is only about 2% lower up to 15⁰ tilt angle. When the harvesting surface is tilted at 30⁰, the condensation rate of the laminar film decreases by 3.5%, while the reduction is 4.7% in wavy-turbulent film condensation. The results indicate that the change in condensation rate is more evident just after 45⁰ tilt. Furthermore, 89⁰ tilted surfaces experience 63.7% and 74.1% lower condensate harvesting in laminar and wavy-turbulent regimes, respectively. In addition, identical horizontal surfaces produce only one fifth condensation rate of a vertical system.

Performance and optimization of a new spray cooling system with PV/T and heat recovery in sow houses: A case study in Nanchang, China

The uncertain cooling effect and additional huge primary energy consumption (EC) caused by humidity regulation are currently the main problems of traditional air-conditioning systems in sow houses. In this paper, a new spray cooling system (NSCS) is developed based on PV/T and heat recovery in sow houses. Compared with traditional spray cooling systems, the cooling efficiency of new system can be significantly improved due to solar dehumidification and its EC can be reduced due to PV/T and heat recovery. Meanwhile, the mathematical models are established for its key equipment and their reliability is verified according to literature data. The results show that the maximum error is less than 7.2 % for the models. Aiming at the maximum utilization rate of cooling and heating equipment, the annual operation modes are determined for NSCS based on the above models. The results show that cooling season is from May 21st to September 25th, heating season is from January 1st to March 16th and from November 1st to December 31st, and the transitional spring and autumn are from March 17th to May 20th and from September 26th to October 31st, respectively. Meanwhile, the optimal spray cooling power (SCP) and mass flow rate of circulating water (MFCW) are obtained by analyzing the operation characteristics of NSCS in cooling and heating seasons. The results show that in cooling and heating seasons, it is suggested to use the minimum ventilation required by sows (42763.5 kg/h) for the ventilation rate of NSCS. Meanwhile, the optimal SCP and MFCW are recommended as 40 kW and 12245 kg/h, respectively. Finally, the matching between exergy efficiency (EE) and EC is analyzed for NSCS in transition season through simulation. The operational control methods are further proposed for NSCS in transition season through optimization. The results show that in transition season, increasing mass flow rate of supply air (MFSA) and reducing equipment power are the operational control methods to obtain the optimal performance and minimum EC of NSCS. Specifically, in the transitional spring, the optimal MFSA, SCP and MFCW are recommended as 47812.0 kg/h, 30 kW and 10245 kg/h, respectively. In the transitional autumn, they are recommended as 55806.3 kg/h, 25 kW and 7245 kg/h, respectively. The above conclusions can provide new ideas for the development of new energy-saving air-conditioning systems in sow houses, and guide the operation control and performance optimization of NSCS.

Increasing energy saving of pilot-scale spray dryers with enhanced yield by low-adhesive surfaces

Spray drying process, widely used in industrial applications, is highly energy-consuming. To reduce the energy consumption under the secured yield, optimizing the operating conditions of drying process or utilizing heat from the exhaust air of dryers has been carried out. Albeit their successful demonstration of energy saving, securing the yield of drying process still requires high temperature processing. Since high temperature processing often degrades or denatures the quality of dried materials in specific applications, further development of diverse strategies is necessitated for yield enhancement in low temperature environments. Herein, a spray drying method with low-adhesive surfaces is proposed to considerably increase the yield of drying process with no additional energy consumption or devices to accomplish the equivalent effects of the enhanced energy saving of spray dryers under the identical operating condition. The experimental results reveal that due to the significant reduction of the particle accumulations in the chamber of the spray dryer, equipping the low-adhesive surfaces to the conical walls of the pilot-scale spray dryer achieves up to 16.5% higher yield than control surfaces under identical operating conditions. This brings about the enhanced energy saving up to 14.2% to acquire the identical powder collection by the spray drying process.

ZnO/Graphene Oxide on Halloysite Nanotubes as a Superabsorbent Nanocomposite Photocatalyst for the Degradation of Organic Dyes

Using renewable photocatalysts for pollutant degradation represents a promising approach to addressing environmental water challenges by harnessing solar energy without additional energy consumption. However, for the practical use of photocatalysts, it is necessary to improve catalyst efficiency, considering cost and biocompatibility. In this study, we developed a new superabsorbent photocatalyst for the degradation of organic dyes in water. Our photocatalyst comprises halloysite nanotubes (HNTs) with a large outer diameter and Si-O and Al-O groups on the outer and inner surfaces, respectively; graphene oxide (GO) possessing numerous sp2 bonds and light-conductive properties; and ZnO, which can degrade organic molecules via a photon source. By exploiting the superabsorbent properties of GOs for organic dyes and stabilizing ZnO nanoparticles on HNTs to inhibit aggregation, our photocatalysts demonstrated significantly improved degradability compared to ZnO nanoparticles alone and combinations of ZnO with HNTs or GO. The structural characteristics of the nanocomposites were characterized using SEM, EDX, Raman spectroscopy, and XRD. Their enhanced photocatalytic activity was demonstrated by the degradation of rhodamine b in water, showing 95% photodegradation under UV illumination for 60 min, while the ZnO nanoparticles showed only 56% dye degradation under the same condition. Additionally, the degradation rate was enhanced by four times. Furthermore, the catalysts maintained their initial activity with no significant loss after four uses, showing their potential for practical implementation in the mass purification of wastewater.

Electromagnetic-acoustic splitter with a tunable splitting ratio based on copper plates.

Acoustic splitters and electromagnetic splitters can be applied in various fields (e.g., navigation and interference detection). However, there is still a lack of study of structures that can simultaneously split acoustic and electromagnetic beams. In this study, a novel, to the best of our knowledge, electromagnetic-acoustic splitter (EAS) based on copper plates is proposed, which can simultaneously produce identical beam-splitting effects for transverse magnetic (TM)-polarized electromagnetic and acoustic waves. Different from previous beam splitters, the beam splitting ratio of the proposed passive EAS can be simply tuned by changing the incident angle of the input beam, i.e., a tunable splitting ratio can be achieved without additional energy consumption. The simulated results verify that the proposed EAS can create two transmitted split beams with a tunable splitting ratio for both electromagnetic and acoustic waves. This may have applications in dual-field navigation/detection, which can provide additional information and higher accuracy compared with single-field navigation/detection.