bluuebunny/crossref_metadata_2025 huggingface dataset:
Visual experimental study on cavitation performance of double-suction centrifugal pump
Authors: Hou Duohua , Li Tongxian , Lu Hongzhong , Yao Zhifeng , Xiao Ruofu , Li Shikang
Published: March 2024

In this paper, the cavitation test results of double-suction centrifugal pump are further “visualized” and verified by using high-speed photography technology to photograph the development process and flow field of impeller inlet cavitation. By optimizing the impeller inlet parameters, the key geometric factors affecting the cavitation performance of the double suction pump were determined. The experimental results show that by optimizing the inlet parameters of the double-suction pump and combining the visualization test verification of cavitation, on the basis of ensuring the wide and efficient efficiency of the double-suction centrifugal pump, the optimization scheme of the experimental design greatly improves its cavitation performance, and provides a new design idea and reference for guiding the development and design of products with high cavitation performance.
Research on the internal pressure pulsation characteristics of reactor coolant pump under non-uniform inflow
Authors: Guo Xi’an , Zhi Yifan , Long Yun , Zhang Mingyu , Qiang Zhuang , Zhu Rongsheng
Published: March 2024

In the third generation of nuclear power technology, the first circuit of the nuclear power plant consists of a steam generator and two vertical reactor coolant pumps (RCPs). The two vertical nuclear pumps are installed upside down at the bottom of the steam generator, resulting in uneven flow at the inlet of the reactor coolant pump due to the special structure of the lower chamber of the steam generator. The RCPs is the sole high-speed rotating machinery in the primary circuit, operating under non-uniform flow conditions for extended periods. The resulting effects on pump performance remain ambiguous. In this study, we focused on the pressure pulsation of the non-uniform flow of a third-generation RCP. To analyze this, we utilized high-precision numerical simulation methods to obtain information regarding the internal pressure pulsation characteristics of the non-uniform inflow. Additionally, we investigated the impact that non-uniform inflow has on the radial force characteristics of the RCP. This study aims to enhance the comprehension of pressure pulsation characteristics in reactor coolant pumps under non-uniform inflows. It will offer valuable insights for research on vibration control in these pumps, and support the development of third-generation nuclear power technology.
Effects of guide vane angle on internal flows and vortex characteristic of reactor coolant pump passage under flow coastdown
Authors: Ye D X , Wen T , Luo Y M , Zhang J Y , Han J M , Deng R
Published: March 2024

In order to explore the effects of guide vane angle on internal flows of reactor coolant pump during flow coastdown, the law of vortex evolution and vortex intensity change in the impeller and guide vanes was analyzed. Based on the second generation vortex identification method: Q criterion, the unsteady evolution law and vortex intensity change of impeller guide vane during flow coastdown were analyzed by numerical simulation. The results show with the flow coastdown, fluctuation law of pressure and velocity in the impeller keeps consistent, while the pressure gradually approaches the outlet pressure and the speed decreases. When the vortex identification’s threshold value is Q=24000 s-2, the vortex area in impeller is small and vortex structure is clear. In a rotation period, the shape and area of vortex structure at the inlet with different guide vane angles are the same. The outlet’s vortex structure is affected by dynamic-static interference, resulting the vortex structure is the same but the vortex area is different. The law of guide vane placement angle changes from “convex-vortex” to “concave -vortex”, and vortex area decreases gradually. In the guide vane, horseshoe vortex is dominant, and structure of blocked vortex and shear layer decreases during flow coastdown.
Spatial distribution of rigid vorticity in pump turbine under turbine mode with different heads
Authors: Yan X T , Kan K , Zheng Y , Chen H X
Published: March 2024

Pump turbines under off-design operating conditions can generate significant vortex structures that cause hydraulic instability in the unit. The aim of this study is to investigate the spatial distribution of large-scale rigid vortex structures in the runner blade channels of a model pump turbine operated under different head conditions with fixed guide vane opening in turbine mode. A new method is proposed that utilizes a relative streamline coordinate system based on mean camber line and provides a unique perspective to quantify the spatial distribution and intensity of various physical variables within the runner blade channels from a novel perspective along the streamwise, circumferential, and spanwise directions. Ultimately, an analysis is conducted on the causes of rigid vortex structures. This paper provides a novel and advanced research technique to analyse unstable flow structures in pump turbines.
A bionic anti-cavitation leading edge for pump-turbine
Authors: Fang Mingkun , Zhang Fangfang , Tao Ran , Liu Weichao , Xiao Ruofu
Published: March 2024

Cavitation is one of the most important technical indicators for assessing reversible pump-turbines. This article describes an anti-cavitation leading edge based on a bionic shape to reduce cavitation. The shape is based on 6 typical fish-like streamlined profiles analyzed in CFD simulations. The flow fields around the profiles were analyzed for different angles of attack to identify the one with the least flow separation and a flat pressure drop. A bionic runner was then built to give an anti-cavitation leading edge. Three-dimensional CFD simulations show that the anti-cavitation leading edge effectively inhibits local flow separation and reduce the pressure drop. Moreover, cavitation tests show that the bionic runner reduces the cavitation inception coefficients. Thus, this design reduces the number of cavitation bubbles and improves the cavitation performance. These results will improve safety and reduce costs and provide a reference for similar hydraulic machinery experiencing.
The effect of damping grid on vortex rope and pressure fluctuation in the draft tube of Francis turbine
Authors: Wang Shanlei , Pang Shujiao , Ding Jiawei , Wang Ming , Chen Zhenmu
Published: March 2024

The pressure fluctuation caused by vortex bands is the main cause of vibration in Francis turbines under off-design conditions. Therefore, adopting effective strategies to affect the vortex rope and suppress the pressure fluctuation caused by the vortex rope is great significance for the stable operation of the Francis turbine. In this study, the damping grid were proposed to optimize the flow state of the fluid in the draft tube, and unsteady numerical simulations were performed to determine their mechanism of action. And a detailed analysis was conducted on the test results to understand the impact of damping grids on the Francis turbine vortex rope. The results show that the pressure fluctuation of draft tube under off-design condition is mainly caused by the low-frequency fluctuation caused by the vortex rope. The damping grid can effectively affect the generation of vortex rope and reduce the low-frequency pressure fluctuation in the Francis turbine.
Study on the optimum design of cross flow water turbines using RSM with weighted least squares method
Authors: Geng Y , Kitahora T , Iio S , Choi Y D , Inagaki M
Published: March 2024

In this study, an optimum design method using the response surface method (RSM) was applied to a cross-flow water turbine in which a circular cavity was installed. The efficiency obtained by CFD analysis was used as the objective function. A quadratic equation for the shape parameters obtained using the weighted least-squares method was used to the response surface. For optimal nozzle design, three shape parameters were used: the runner opening angle, nozzle wall exit angle, and radius of curvature of the nozzle wall. In the weighted least-squares method, the weights of the residual between the efficiency obtained from CFD analysis and the value from the response surface were defined as inversely proportional to the root mean square of the difference between the efficiency of the calculation point from CFD and that at the highest efficiency point, such that more accurate optimal values could be estimated. The shape derived using this optimum method achieved high efficiency.
The influence mechanism of asymmetric distribution characteristics of erosion in the injector of Pelton turbines
Authors: Li Fang , Li Chenxi , Sun Shuaihui
Published: March 2024

To analyze the influence mechanism of asymmetric erosion distribution characteristics in the injector of the Pelton turbine, a detailed analysis of erosion amount and distribution characteristics within different regions of the nozzle and needle is conducted, elucidating the motion and distribution characteristics of sediment particles. The Euler-Lagrange method is used to numerically calculate the flow process of sediment particles with a concentration of 2% and diameters of 0.1mm, 0.5mm, 0.75mm, 1mm, and 2mm in the injector, and the erosion amount is estimated. The results show that the sediment particle diameter significantly influences the symmetry of erosion distribution in the injector. When the diameter gradually increases, the symmetrical phenomenon gradually disappears. Furthermore, the influence of sediment particle diameter on erosion degree within different regions of the injector is inconsistent. With the increase of sediment particle diameter, the average erosion rate of the needle increases. While the average erosion rate in the guide plate area of the nozzle decreases at first and then increases, the nozzle throat is reversed. The guide plate affects the distribution and movement of sediment particles at its end, aggravating the asymmetric erosion phenomenon at the nozzle, especially on the small particle size sediment.
Development and experimental study of a kind of fluidic sprinkler
Authors: Zhu Xingye , Kong Jing , Solangi Farheen , Yu Pengpeng
Published: March 2024

In this paper, a new variety of fluidic sprinkler was introduced and its working principle was presented. An auto-testing system of water distribution was established. The technology using rain-collection as an implement used RS485 assembly line for installation. Angle and frequency of step-by-step are effective driving moment operation of the fluidic sprinkler. The water distribution of fluidic sprinkler types 10 to 50 under relevant operating pressures was pointed out. Experimental results demonstrated that the fluidic sprinklers have complied with the national standards in flow, uniform coefficient, range and so on, which was supposed to be substitute samples for impact sprinkler in the future.
Study on the influence of different structural parameters on the performance of Tesla valve
Authors: Zhang Xinchen , Cao Zhengqing , Fang Kaiyue , Yang Xuelong
Published: March 2024

In this paper, the fluid flow of Tesla valve after the change of three structural parameters, such as diverting Angle, bend outlet width and stages, is analyzed, and their effects on the performance of Tesla valve single channel are studied. The results show that the Di value of the Tesla valve presents an upward trend with the increase of the three parameters, that is, the performance of the single pilot pass is getting better and better, but the improvement of its performance will be limited to a certain extent. When the diverting Angle increases, the pressure drop and energy loss caused by the reverse flow of the fluid will be larger, but if the diverting Angle is too large, the forward flow of the fluid in the Tesla valve will be affected. When the width of the bend outlet increases to a certain size, the fluid flowing into the bend pipe is close to the upper limit, and the single pilot performance of the Tesla valve will not be greatly improved. The increase of multiple Tesla valve stages has an effect on both forward and reverse flow of fluid.
Research on aerodynamic influence of contra-rotating propfan slipstream on propfan engine nacelle inlet
Authors: Zhao Haiyu , Zhou Li , Deng Wenjian , Wang Zhanxue
Published: March 2024

In order to investigate the aerodynamic influence of contra-rotating propfan (CRP) slipstream on propfan engine nacelle, numerical simulation research on the CRP/Nacelle integrated configuration was carried out by using sliding mesh unsteady method. The aerodynamic performance of integrated configuration under different working conditions was studied, and compared with nacelle without CRP. Results show that the total pressure recovery coefficient of inlet port increases due to the work done by CRP. However, as the inhale of the wake vortex, the flow structure inside the inlet becomes more complex because of the mixing of wake vortex and wall separation vortex, which leads to a significant increase of distortion index and loss coefficient. Compared with isolated nacelle, the slipstream causes the total pressure recovery coefficient of inlet port increased by 10.2% and 13.4% under cruise condition and takeoff condition, which is accompanied by the intensification of flow loss and non-uniformity inside the inlet, resulting in a significant increase of the total pressure loss coefficient and total pressure distortion index.
Evaluation of the prototype performance of Wanjiazhai Francis turbine with flow pattern analysis
Authors: Liu Xinjun , Lu Jiahao , Luan Shaoshuai , Song Xijie , Wang Zhengwei , Zhu Di , Tao Ran
Published: March 2024

Multiple Francis turbines are installed in Wanjiazhai water conservancy project to generate electricity, and the operating conditions of the units vary greatly. Because the unit head itself is not high, and the parameters such as head, flow and output vary widely, the operation of the unit becomes very complex. Aiming at this problem, this study predicts and analyzes different typical operating conditions during the operation of the unit, and compares them with the field measured results. The analysis of Prototype unit helps us understand the actual flow state inside the unit and observe the possible complex flow phenomenon. Therefore, the distribution of vortices inside the unit is analyzed in depth, and the flow structures inside the volute, stay vane, guide vane, runner and draft tube are compared to serve the safe and stable operation.
Effect of working fluid on the ORC cycle performance of the ocean thermal energy conversion system
Authors: Zhang Kai , Lv Xiaojing , Weng Yiwu
Published: March 2024

Ocean Thermal Energy Conversion system utilizes shallow seawater as the heat source and deep seawater as the cold source, achieving energy conversion at low temperatures and small temperature differences. To improve the efficiency of the OTEC system, this paper focuses on the working fluid side, based on the closed Organic Rankine Cycle, to analyse and select common low boiling point organic working fluids suitable for the OTEC system. Two of them are combined to form new mixed fluids with different component types and ratios. The impact of different types of mixed fluids on system performance is studied. Results show that M31 mixed working fluid has higher power generation efficiency, lower operation pressure and the best economical. Peak ƞOTEC
is 6.43. Compared with pure fluids, using mixed fluids greatly reduces the power consumption and the frictional resistance loss. The R245fa/R245ca (0.3/0.7) mixed working fluid has the smallest power consumption among all its component allocation ratios, with a deep seawater pump consuming 5.085kW, accounting for only 3.3% of that when using pure R245ca. Compared to pure fluids, mixed fluids have higher net output power. So, M31 can be selected as the most suitable working fluids for OTEC system among M1 to M36.
Numerical investigation of the powered take-off configuration of civil transport using an improved thrust-drag bookkeeping method
Authors: Cui Zheng , Zhang Wensheng , Wang Kai , Cao Yihua
Published: March 2024

This paper offers a detailed examination of the powered nacelle’s effect on take-off configuration of a civil transport. Using computational fluid dynamics (CFD) techniques, we analyzed two specific geometries from the Propulsion Aerodynamics Workshop and High-lift Prediction Workshop, comparing our results with existing experimental data. We incorporated configurations of both the Through-flow Nacelle (TFN) and Power Nacelle (PN) for a comprehensive comparison. Our approach significantly refined the prevailing thrust-drag accounting method. Employing surface flow visualizations and spatial particle trajectories, we highlighted the powered nacelle’s influence on the aircraft flow field. Simulations show that the engine exhaust’s flow acceleration boosts lift and reduces flow separation at high angles of attack. However, power intervention notably increases the overall drag. Specifically, at a 14° angle of attack, power effects raise the drag coefficient of the take-off configuration by 275 counts, resulting in a 0.76 decrease in the lift-to-drag ratio.
Investigation on suitable design parameters for hydrodynamic bearing of LVADs
Authors: Li H Y , Zhang M K , Wu Q Y , Luo X W
Published: March 2024

Left ventricular assist devices (LVADs) are crucial and helpful to support heart function for patients with heart failure. For the LVAD with hydrodynamic bearings, high reliability of the bearing is necessary to support the rotor and achieve the performance of LVADs. This research investigates the effect of various design parameters on the performance of a dislocated hydrodynamic bearing in LVAD based on numerical simulation, where Reynolds equation is solved to simulate the behaviour of the bearing under different design conditions. For the design of hydrodynamic bearing, several parameters are considered, such as wedge number, wedge depth, wrap angle, bearing clearance, length-diameter ratio, etc. The results show the effects of these parameters on friction loss, supporting capability, and so on. The optimal hydrodynamic bearing design is proposed so as to improve the performance of LVADs.
Multi-objective optimization of intake parameters based on response surface methodology
Authors: Fang T , Huang X B , Yu K , Guo Q
Published: March 2024

The open intake is an important hydraulic building in pumping stations. This paper adopts the simple coupled level-set and volume of fluid and bifurcation model for numerical simulation. Based on the response surface methodology (RSM), multi-objective optimization of the structural parameters of the open intake is carried out. Considering the air-entrained vortex and irreversible energy loss of the intake pool, the response surface optimization model of the intake is established. The results verify the accuracy of this model. It is shown that the influence of floor clearance and back-wall clearance on the objective function is significant; After gradient optimization calculation, the optimal parameter combination is C = 0.4172D and B = 0.7208D. This optimization scheme suppressed the air-entrained vortex and other adverse flow patterns. And these results provide relevant theoretical references for the future design of intake.
Analysis of wind power level distribution in drainage corridor under runner return-exhaust condition
Authors: Shu Lingfeng , Long Zhe , Wu Jiawei , Li Chengjun
Published: March 2024

When pumped storage units are operated under return-exhaust conditions, there are areas of high wind speed in the drainage corridor, which seriously threaten the life safety of the operating personnel. In actual operation, accidents such as exhaust pipe breakage and water spraying frequently occur in power stations, which also cause significant property losses. Currently, there is a scarcity of studies on the wind distribution in the drainage corridor for the return exhaust condition, and there is a lack of quantitative knowledge on the design and risk assessment of the range of wind speed safety zones in the region. In this paper, a full-channel unsteady numerical simulation is carried out using the SST turbulence model for the backwater exhaust condition of a pumped storage power station’s dewatering air system, focusing on the wind distribution in the drainage corridor, analyzing and summarizing the specific mechanism of wind distribution. The results show that the main factor determining the wind distribution in the drainage corridor under the backwater exhaust condition is the jet velocity at the outlet of the exhaust main pipe, and the size of the outlet jet velocity is related to the orifice valve, the diameter of the exhaust pipe and the structure of the outlet, which can provide data support for the safe area delineation of the drainage corridor of the dewatering air system and the pre-design of the corridor.
Thermal-hydraulic performance analysis of the supercritical fuel printed circuit heat exchanger with zigzag flow channels
Authors: Wei Yingchuan , Li Xiang , Zhu Jianqin , Cheng Zeyuan , Wei Jiaqi
Published: March 2024

Printed Circuit Heat Exchanger (PCHE), which uses the supercritical fuel RP-3 as the cold fluid and the air as the hot fluid, is considered a promising candidate for CCA (Cooled Cooling Air) system heat exchanger selection due to its high compactness and efficiency. In this paper, the numerical method of the supercritical fuel PCHE with Zigzag channels is established, and an experimental system is designed and built to verify the accuracy of the numerical method. The influence of inlet temperature, mass flow rate, and outlet pressure of the fuel on the thermal-hydraulic performance is numerically investigated. The inlet temperature of fuel is ranged from 100 to 500°C, the mass flow rate of fuel is from 6 to 10g/s, and the outlet pressure of fuel is ranged from 3 to 6MPa. The results demonstrate that the fuel exhibits higher heat transfer coefficients and pressure drop caused by higher mean turbulent kinetic energy as the increase of the inlet temperature and mass flow rate. The flow and heat transfer performance of the fuel does not change significantly with pressure change since its thermophysical properties decrease slightly with increased pressure. The flow and heat transfer correlations for the tested PCHE are proposed with the numerical results. The newly developed Fanning friction factor correlation predicts almost 100% of the numerical data within the ±5% error band, and the newly developed heat transfer correlation predicts 94.4% of the numerical data within the ±10% error band.
Characterizing the hydration process of cement based on synchronous thermal analysis method
Authors: Wu Chuandeng
Published: March 2024

Research on the characterization method of cement hydration progress - synchronous thermal analysis cement hydration progress is closely related to the strength of cement concrete materials. How to intuitively and effectively characterize cement hydration progress has been puzzling by researchers in this field. In this project, the content of various hydration products in the thermal analysis process of cement slurry and its variation law with age were obtained by simultaneous thermal analysis of the benchmark cement and the benchmark cement doped with early strength agent ZQ-1. By comparing the three DTG spectra of cement slurry mixed with early strength agent and blank benchmark cement slurry with maximum thermal weight loss on thermal decomposition, calcium hydroxide of hydration products with peak temperature between 400°C ~ 450°C can better characterize the effect of different admixtures on the hydration process of cement slurry. Early strength admixtures can better promote the early hydration of benchmark cement.
Study on sintering properties of aluminum oxide nano-powder for electronics packaging
Authors: Lin Meihong , Huang Yongliang , Ran Chenxiu , Dong Guangcheng , Zhao Yan
Published: March 2024

The microstructures of two kinds of nano powders (ɑ-Al2O3, γ-Al2O3) are studied using a scanning electron microscope (SEM), X-ray diffraction (XRD) under the customized low-temperature sintering process (under the maximum sintering temperature 1600 °C) for the frame material of the customized ceramic for high power electronics packaging application. The experimental results show that the structure of ɑ-Al2O3 is stable while the structure of γ-Al2O3 is unstable. The crystalline form of γ-Al2O3 is changed to ɑ-Al2O3 under the sintering process. The two kinds of powders are all bonded together with a laminate structure. The sintered samples of the γ-Al2O3 are the most compacted.
Study on the influence of environmentally friendly plasticizers on the properties of polyvinyl chloride
Authors: Wu Hailong , Zhou Biyun , Cen Chuanfu , Cao Yu
Published: March 2024

In this work, the torque rheology, mechanical properties, migration resistance, thermal deformation, and Vicat softening point temperature of PVC plasticized by four environmentally friendly plasticizers are investigated. The experimental results reveal that the plasticizer’s heavy metal content meets production requirements while falling below the limiting standard. Plasticizer melting points differ, as do the enthalpy and torque of the entire melting process, resulting in different energy consumption when melting plasticizers. Also, the mechanical properties of PVC are not different, but the mechanical properties of PVC plasticized by epoxy soybean oil are the most prominent. Besides, the Vicat softening point temperature of PVC plasticized by four environmentally friendly plasticizers is within the normal standard range, and the migration amount in different solvents is changed in a small range, which will not affect human health.
Study on the protective performance of coating system for thermal spraying zinc on radar
Authors: Yang Junhua , Wang Wei , Lu Yang , Zhu Lizhi , Jia Xue , Wang Qiang
Published: March 2024

In response to the harsh marine environment protection needs of radar, the protective performance of 9 types of coating systems for thermal spraying zinc was studied through condensation tests, salt spray tests, and temperature tests. The blistering phenomenon of the radar thermal spraying zinc matching protective coating system was analyzed. The research results showed that the blistering of the thermal spraying zinc matching protective coating system may be related to the pores of the sealing coating. Among the 9 coating systems, the comprehensive performance of B and D coating systems in terms of moisture resistance, salt spray resistance, and temperature stress resistance is significantly superior to other coatings. The radar using B and D coating systems has been successfully applied to various types of harsh marine environments, improving the radar’s protective performance.
Research on antennas based on nanophotonic materials
Authors: Huang Honghua , Che Lidong , Chen Youwei
Published: March 2024

In this study, the performance of bilayer graphene and its dual-frequency reconfigurable antenna structure on SiO2/Si substrates was explored. The research underscores that when compared to traditional radio frequency and microwave antennas, the performance of nano-optical antennas is strongly contingent on their size and shape. It is also intimately related to their intrinsic material properties, highlighting the unique physical attributes and scaling behavior of nano-photonic antennas. A salient feature of bilayer graphene is its ability to dynamically adjust its conductivity by applying an external voltage between the two layers, offering new prospects for its application in micro-nano electronics and photonics. Through a comparative analysis of radiation decay rates and quantum efficiency, it was determined that metallic materials exhibit much higher non-radiative losses than nano-optical materials. This research provides a foundational theoretical framework for future experiments and paves the way for creating secure information networks. However, the study acknowledges the potential challenges in the real-world application and production of nano-photonic antennas, suggesting further exploration in optimizing their structure to enhance efficiency.
Influence of parameter on the characteristics and morphology of Ni60/WC coatings
Authors: Feng Mingjia
Published: March 2024

Due to its unique excellent performance, titanium alloys have a broader set of uses. With the increasing use of titanium alloys, there are also certain problems when used in some special environments, for example, poor wear resistance and oxidation resistance. To address the wear resistance and ensure its application is not limited by conditions, this article uses the laser method to prepare Ni60+35% WC composite coverings on Ti6Al4V alloy using different scanning speeds (8, 12, 14 mm/s). Findings indicated the laser-clad wall coverings at three different speeds achieved strong metallurgical adhesion between the substrates. The phenomenon of mutual diffusion between Ti6Al4V alloy and coating materials was observed, and the coating’s microhardness grew as the scanning speed rose. When compared with the substrate, the surface coating’s anti-wear properties were increased. At 14 mm/s scanning, the covering exhibited the highest durability to wear.
Effect of sintering insulation temperature on the properties and microstructure of alumina-reinforced aluminum matrix composites
Authors: Zou Haiping , Yu Xiaohong , Wu Hongliang
Published: March 2024

Aluminum matrix composites reinforced with particles have garnered significant attention due to the growing need for advanced structural materials. This research utilized nano-Al2O3 powder (30 nm in size) and pure aluminum powder (40 μm in size) as raw materials to fabricate alumina-reinforced aluminum matrix composites through the hot-pressing powder metallurgy sintering method. The raw powders were amalgamated using mechanical ball milling and ultrasonic dispersion. This paper delves into the relative densities, hardness, and other properties of the alumina-reinforced aluminum matrix composites, emphasizing the impact of the sintering insulation temperature on these attributes and microstructures. The result showed that the optimal sintering insulation temperature was identified as 400°C, where the Vickers hardness (HV0.5) peaked at 31.3 HV and the relative density reached a zenith of 0.986. SEM imagery revealed that the white nano-Al2O3 particles were evenly dispersed across the silver-white aluminum matrix, with no evident clumping. Furthermore, the nexus between the nano-Al2O3 particles and the composite matrix was seamless and robust. Such features enhance the composite’s performance. The research underscores the potential of enhancing these composites and posits that alumina-reinforced aluminum matrix composites can be effectively produced using the hot-press powder metallurgy sintering technique.
Preparation of porous nano-magnesium oxide using a corn starch template method
Authors: Chen Hukui , Mu Xiaxia , Jiang Yu , He Zhijun
Published: March 2024

Nano-porous magnesium oxide was prepared using a corn starch template and a magnesium nitrate hexahydrate precursor, and characterized by TGA, XRD, FTIR, EDS, TEM, and BET surface area analysis. The results showed that porous magnesium oxide composed of nano-particles could be obtained using this method. The final magnesium oxide product was in the form of large flakes under low magnification, and the flakes were composed of small nano-scale particles under high magnification. The particle size of nano-porous magnesium oxide was 20–28 nm, the specific surface area was 29.37 m2/g, and the average pore diameter was 19 nm.
Corrosion Assessment of Metals in the Presence of Food Waste Fermentation Solution Through the Experimental Study
Authors: Shi Quan , Wu Xuan , Shen Lin , Li Xueqin
Published: March 2024

This paper describes an experimental study on the corrosion assessment of metals in the food waste fermentation solution. The corrosive degree of metals under different submersion conditions is assessed through the weight loss method. The experimental results indicate that HT200, Q345B, and 45 steel are rapidly corroded (weight loss values over 80, 221 mg/m2 after 192 hours). Although 304 shows a better corrosion-resistant ability, it is slightly corroded (weight loss: 1, 782 mg/m2 after 192 hours) under the interval submersion condition. The food waste treatment facilities, especially pipelines, and bioreactors should avoid iron-based materials.
Design of the Ti-PCL interpenetrating phase composites with the minimal surface for property enhancement of orthopedic implants
Authors: Xie Haiqiong , Chen Junjie , Liu Fei , Luo Tao , Wang Yiru , Tang Yichuan
Published: March 2024

IPCs (interpenetrating phase composites) offer a promising approach to enhancing the mechanical properties of orthopedic implants, including strength, fracture toughness, and the potential for incorporating complex functionalities. In this study, Ti6Al4V-PCL IPCs were fabricated by additive manufacturing and infiltrating melted PCL into a Ti6Al4V scaffold with a minimal surface structure. The IPCs introduction modifies the specimen’s failure mode and improves its energy absorption performance through enhanced two-phase interaction and effective stress transfer. Finite element simulations demonstrate increased stress diffusion, improved energy absorption mechanisms, and a prolonged stress plateau period. Among various scaffold types, the Gyroid IPCs exhibit superior mechanical properties, making them an excellent choice for enhancing the performance and functional development of degradable implantable stents.
Research progress of Fe/Al2O3 interface based on first principles
Authors: Yu Qing , Guo Dong , Deng Xiaohu , Zhao Dongfeng , Meng Shuang
Published: March 2024

Fe-Al alloy has excellent oxidation resistance and has a good application prospect in high-temperature environments. Its oxidation resistance mainly comes from the Al2O3 oxide film on the surface, and the Fe/Al2O3 interface is the weakest link between the oxide film and the substrate. With the development of computational materials science, using first-principles calculations to study the Fe/Al2O3 interface has gradually become a research topic of concern. According to the different construction methods of the Fe/Al2O3 interface, the existing theoretical models of Fe/Al2O3 interface structure are divided into three categories: γ-Fe/α-Al2O3 interface model, α-Fe/α-Al2O3 interface model and other Fe/Al2O3 interface models. Their characteristics are compared and analyzed. The latest research results of Fe/Al2O3 interface optimization measures and strengthening mechanisms are listed, and a summary of how alloying elements affect the ability of Fe/Al2O3 interface bonding is provided. The study of strengthening mechanisms can lead to better design of interfaces for new materials and thus improve material properties.
From spent lithium ion battery to supercapacitors: a green and facile approach for recovering carbon-based anode materials
Authors: Song Shanshan , Deng Danli , Lu Yingjun , Fan Wenjie , Xu Wanli
Published: March 2024

With the rapid development of electric vehicles and boosting lithium-ion battery production, recycling waste lithium-ion batteries has been the focus for researchers all over the world. In this study, carbon material was recovered via forming lithium graphite intercalated compound through charging and followed by high energy ball milling. The recovered carbon sample was then prepared as electrodes for symmetric supercapacitors. Electrochemical tests and material characterizations showed that the recovered carbon has a porous graphene-like sheet structure, and the specific surface area and specific capacitance can be effectively increased to 155 m²/g, which is over 10 times higher than that of the untreated carbon. The maximum specific capacitance of recovered carbon material was 41.66 F/g at a scan rate of 100 mV/s with a voltage range of 0-2V, which is 10 times higher than that of untreated carbon. The green and facile recovery method of batteries proposed in this paper provides a new idea and method for the recycling and utilization of waste lithium-ion battery anode materials.
A handy preparation of Pt-based bulk catalysts for indoor formaldehyde purification
Authors: Xie Junming , Huang Yanting , Tu Shunheng , Deng Kang , Li Yongfeng
Published: March 2024

This paper mainly studies the preparation of Pt-based bulk combustion catalysts using cordierite honeycomb ceramics as the substrate, and chemical plating technology to directly load precious metal Pt on the sensitized and activated ceramics. Formaldehyde was used as the reaction gas for performance testing of the combustion catalytic activity of the catalyst. The XRD and SEM results have shown that the Pt particles were loaded on the face of cordierite. The effect of formaldehyde purification is significantly affected by factors such as the initial concentration of formaldehyde in the closed space, environmental humidity, and catalyst calcination temperature.
Experimental investigation of spin coating acceleration effect on the DSSC performance
Authors: Yıldız Yusuf , Bilen Kemal , Atılgan Abdullah
Published: March 2024

The optimization of the TiO2 mesoporous structure plays significant role in dye-sensitized solar cell (DSSC) to produce efficient devices. In this study, the TiO2 mesoporous layer was coated by using a spin coating equipment with different spin accelerations. As a consequence of this investigation, the impacts of the spin coating acceleration on the optoelectronic and electrical performance characteristics of the DSSC were investigated. It has been shown that altering the spin coating acceleration has a direct impact on the mesoporous layer, which in turn influences the absorption ability of dye. The light absorbance of the sample A5 (coated at 2000 rpm s−1) ascended drastically in accordance to other samples. Thanks to this augmentation in absorbance, the current density (J

SC
) and power conversion efficiency (PCE) values also improved. According to electrochemical impedance spectroscopy analysis, it was attained that recombination resistance values increases with the rising spin coating acceleration rates after 500 rpm s−1 and reaches up to highest value at 2000 rpm s−1. A relatively longer electron lifetime of 40.36 ms and recombination resistance of 12.22 Ω were obtained for the device coated at the rate of 2000 rpm s−1. The device coated at a rate of 2000 rpm s−1 had a PCE (5.51%) that was superior than other devices because of its improved light collecting ability, quick electron transport, suppressed electron recombination, and having longer electron life time. As a starting point for future investigations and applications, results of present study provide an insight into the optimal spin coating parameters for DSSC applications.
Light found to evaporate water without heat
Authors: Dumé Isabelle
Published: March 2024

Researchers in the US have found that under certain conditions light can cause water to evaporate directly, without heating it first.
Quantum processor integrates 48 logical qubits
Authors: Jarman Sam
Published: March 2024

A quantum processor with 48 logical qubits that can execute algorithms while correcting errors in real time has been unveiled in the US.
Qubits made with entangled molecules
Authors: Boerkamp Martijn
Published: March 2024

Two independent groups report using ultracold molecules to encode quantum bits, as Martijn Boerkamp explains.
UK student exchange Turing Scheme ‘inadequate’
Authors: Allen Michael
Published: March 2024

Universities and colleges have found it hard to complete applications to the UK’s new Turing Scheme, with funding for students often delivered late, according to a report.
Physicist Maggie Aderin-Pocock honoured with damehood
Authors: Banks Michael
Published: March 2024

Physicist Maggie Aderin-Pocock, who is chancellor of the University of Leicester, has been awarded the title Dame Commander of the Order of the British Empire for services to science education and to diversity.
The power of quantum algorithms
Authors: Johnston Hamish
Published: March 2024

Building quantum computers isn’t just about developing clever new hardware. Toby Cubitt, who co-founded the quantum-tech firm Phasecraft, tells Hamish Johnston why algorithms are vital too.
What if the Internet broke?
Authors: Randall Ian
Published: March 2024

Ian Randall reviews Communications Breakdown: SF Stories about the Future of Connection edited by Jonathan Strahan.
The principles of chaos
Authors: Flack Jessica
Published: March 2024

Jessica Flack reviews The Primacy of Doubt by Tim Palmer.
Ask me anything: Margaret Gardel
Authors: Harris Margaret
Published: March 2024

Margaret Gardel is a biophysicist and professor at the University of Chicago, US, where she is director of the new Center for Living Systems – one of four newly established National Science Foundation Physics Frontier Centers.
Physics in the round
Authors: Perkowitz Sidney
Published: March 2024

Sidney Perkowitz explains what Isaac Newton has to do with a huge entertainment dome in Las Vegas.
Enhancing the indoor performance of organic photovoltaic devices: interface engineering with an aminobenzoic-acid-based self-assembled monolayer
Authors: Oh Seunghyun , Kang Yelim , Kim Tae Hyuk , Kim Seon Joong , Lee Min Jong , Lee Gyeong Min , Saeed Muhammad Ahsan , Shim Jae Won
Published: March 2024

Significant advances in the performance of organic photovoltaic (OPV) devices can facilitate their use in internet of things applications. However, achieving excellent photostability and high efficiency using stable, efficient OPV devices in indoor settings is considerably difficult. To address this issue, a zinc oxide (ZnO) electron transport layer (ETL) was modified with a self-assembled monolayer of 4-aminobenzoic acid (ABA) in the present study, and the impact of this modification was correlated with the indoor performance of an OPV device with the PM6:L8-BO photoactive layer. The ABA-treated ZnO ETL exhibited a significant reduction in the work function (from 4.51 to 4.04 eV), surface roughness (from 0.201 to 0.177 nm), and hydrophilicity of an indium-tin-oxide electrode; this aided in selectively extracting charge carriers from the device and minimizing trap-assisted recombination losses. Additionally, the ABA treatment of the ZnO ETL considerably enhanced the electron mobility and recombination resistance. It reduced the trap density, thereby enabling the ZnO/ABA-based device to achieve improved performance. Consequently, the ZnO/ABA-based device exhibited a noteworthy 14.68% higher maximum power output than that of the device without any ZnO surface modification under 1000 lx halogen (HLG) illumination (P
out, max = 354.48 and 309 µA cm−2, respectively). Moreover, under thermal illumination conditions (1000 lx HLG lighting), the ZnO/ABA-based device sustained ∼74% of its initial power conversion efficiency over 120 h, significantly higher than its ABA-free equivalent (∼55%).
Recent progress towards smart transportation systems using triboelectric nanogenerators
Authors: Nguyen Minh Phuong , Huynh Nghia Dinh , Luu Thien Trung , Choi Dukhyun
Published: March 2024

The field of transportation plays a crucial role in the development of society. It is vital to establish a smart transportation system to increase the convenience and security of human life. The incorporation of artificial intelligence and the internet of things into the traffic system has facilitated the emergence of innovative technologies like autonomous vehicles or unmanned aerial vehicles, which contribute to the reduction of traffic accidents and the liberation of human driving time. However, this improvement involves the use of multiple sensor devices that need external power sources. As a result, pollution occurs, as do increases in manufacturing costs. Therefore, the quest to develop sustainable energy remains a formidable obstacle. Triboelectric nanogenerators (TENGs) have emerged as a possible solution for addressing this problem owing to their exceptional performance and simple design. This article explores the use of TENG-based self-power sensors and their potential applications in the field of transportation. Furthermore, the data collected for this study might aid readers in enhancing their comprehension of the benefits linked to the use of these technologies to promote their creative ability.
Advancements and challenges in additive manufacturing: a comprehensive review
Authors: Chattopadhyay Subhajit , Mahapatra Stephen Dilip , Mandal Nirmal Kumar
Published: March 2024

Additive manufacturing is an innovative new technology in which layers of materials are added strategically to produce three-dimensional structures. Over the course of recent years, it has undergone remarkable advancements, enabling the realization of intricate designs, shortening production timelines, and causing a transformative shift in manufacturing protocols. This comprehensive article examines the most recent advances and problems in additive manufacturing. The present paper provides a concise overview of the fundamental principles and methodologies of additive manufacturing. Subsequently, it delves into the latest advancements and cutting-edge technologies in this domain, including multimedia printing, bio printing, and metal 3D printing. Finally, this study concludes with future prospects and directions of this technology.
Detection of limit cycle signatures of El Niño in models and observations using reservoir computing
Authors: Guardamagna Francesco , Wieners Claudia , Fang Xianghui , Dijkstra Henk A
Published: March 2024

While the physics of the El Niño–Southern Oscillation (ENSO) phenomenon in the Tropical Pacific is quite well understood, there is still debate on several more fundamental aspects. The focus of this paper is on one of these issues that deals with whether ENSO variability, within the recharge-discharge oscillator theory arising from a stochastic Hopf bifurcation, is subcritical or supercritical. Using a Reservoir Computing method, we develop a criticality index as an indicator for the presence of a limit cycle in noisy time series. The utility of this index is shown in three members of a hierarchy of ENSO models: a conceptual box model, the classical Zebiak-Cane model and a state-of-the-art Global Climate Model. Finally, the criticality index is determined from observations, leading to the result that ENSO variability appears to be subcritical.
Reconstructing supply networks
Authors: Mungo Luca , Brintrup Alexandra , Garlaschelli Diego , Lafond François
Published: March 2024

Network reconstruction is a well-developed sub-field of network science, but it has only recently been applied to production networks, where nodes are firms and edges represent customer-supplier relationships. We review the literature that has flourished to infer the topology of these networks by partial, aggregate, or indirect observation of the data. We discuss why this is an important endeavour, what needs to be reconstructed, what makes it different from other network reconstruction problems, and how different researchers have approached the problem. We conclude with a research agenda.
Women in power: the role of gender in renewable energy policymaking
Authors: Bansal Mriga , D’Agosti Natalia
Published: March 2024

Do female policymakers encourage the production of renewable energy compared to their male counterparts? Using instrumental variables, we conduct a cross-country analysis of 39 high-income countries for the years 1997–2020 using quota laws and women’s suffrage as instruments for women’s participation in the parliament. We find that a 1 percentage point increase in the proportion of women in the legislature increases renewable energy production by 1.54 percentage points. This study suggests that fostering policies that boost women’s participation in policy-making positions is beneficial, especially when considering the positive spillover to other countries.