Penetration Rate Research Articles

Achieving superior Laplace pressure in electrospun PVDF/PAN Janus membranes: A morphological approach

Janus membranes have asymmetric wettability on each side. This contrasting structure gives them an internal driving force for spontaneous fluid transport (caused by Laplace pressure). The objective of this research is to attain the maximum Laplace pressure for electrospun PVDF/PAN Janus membranes by adjusting the fiber diameter and, consequently, the pore size and contact angle in each layer of the membrane. To achieve this goal, the Taguchi method was employed, and the parameters of the electrospinning process were modified to determine the optimal conditions for obtaining the smallest and largest fiber diameters for PAN and PVDF polymers. Accordingly, four distinct types of Janus membranes with different morphologies in each layer were synthesized. SEM analysis was employed to characterize the structural and morphological properties of the fibers in each layer. Additionally, the contact angle (CA) was measured to assess the hydrophilicity of each layer and determine the droplet penetration rate across the membrane. According to the results, the maximum Laplace pressure (205.60 kPa calculated by the analysis of SEM images and 197.4 kPa calculated by the bubble point test) and highest droplet penetration rate (0.83 µL/s) were attributed to the Janus membrane with the lowest pore size in the hydrophilic layer (0.65 µm) and the highest pore size in the hydrophobic layer (3.44 µm). The performance of the optimized membrane was evaluated with respect to unidirectional water transport and water–oil mixture separation. The results showed a rectification ratio of3.92, a permeate flux of7.9 × 104 L·m−2·h−1·bar−1, and a separation efficiency of96.8 %. Finally, it was demonstrated that the Laplace pressure of the optimal Janus membrane in this study is 2.66 times superior to that of the best similar one in previous studies. The appropriate and allowable range for pore size and contact angle, necessary to attain a satisfactory Laplace pressure (exceeding 100 kPa), has been explored, determined, and recommended for future researchers to foster inspiration in the field of Janus membranes.

Time-Delay Following Model for Connected and Automated Vehicles Considering Multiple Vehicle Safety Potential Fields

Connected and automated vehicles (CAVs) represent a significant development in the transport industry owing to their intelligent and interconnected features. Potential field theory has been extensively used to model CAV driving behaviour owing to its objectivity, universality, and measurability. However, existing car-following models do not consider the impact of time delays and the influence of information from multiple vehicles ahead and behind. This paper focuses on the driving-safety risks associated with CAVs, aiming to enhance vehicle safety and reliability during travelling. We developed a multi-vehicle car-following model based on safety potential fields (MIDM-SPF), taking into account the characteristics of multi-vehicle connected information and time delays. To enhance the model’s precision, real-world data from urban roads were employed, alongside an improved optimisation algorithm to fine-tune the car-following model. The simulation experiment revealed that MIDM-SPF significantly reduces stop-and-go traffic, thereby improving traffic flow stability in urban areas. Additionally, we validated the stability of our model under varying market penetration rates in large-scale mixed traffic. Our findings indicate that increasing the CAV proportion improves the stability of mixed traffic flows, which has important implications for alleviating traffic congestion and guiding the large-scale implementation of autonomous driving in the future.

Atomic force microscopic investigations of transient early-stage bacterial adhesion and antibacterial activity of silver and ceria modified bioactive glass

Bioactive glass 58S (BG58S) is widely recognised for its bioactivity and antibacterial properties, making it a promising material for orthopaedic implant applications. This study investigates the effects of incorporating silver (BG58S-2.5Ag) and cerium oxide (BG58S-5C) into BG58S on early-stage bacterial adhesion and subsequent bacterial growth inhibition. Using a high-intensity ball milling approach, BG58S was modified with 5% cerium oxide (CeO2) and 2.5% silver (Ag) nanoparticles to create homogeneous BG58S-2.5Ag and BG58S-5C nanocomposites. Custom-made biomineral probes were employed to measure the bacterial adhesion within one second of contact with Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, using Atomic Force Microscopy (AFM). The results demonstrated that BG58S-2.5Ag showed significantly stronger transient adhesion to bacteria compared to BG58S, leading to a more effective long-term antibacterial response. Additionally, it was observed that the antibacterial effect of Ag commenced within one second of contact. These findings indicate a potential correlation between the rate of bond strengthening and cell wall penetration. This study highlights the potential for enhancing the effectiveness of antibacterial implant surfaces for various biomaterial applications.Graphical abstract

Power supply characterization of baseload and flexible enhanced geothermal systems

We investigated the techno-economic feasibility and power supply potential of enhanced geothermal systems (EGS) across the contiguous United States using a new subsurface temperature model and detailed simulations of EGS project life cycle. Under business-as-usual scenarios and across depths of 1–7 kilometers, we estimated 82,945 GW and 0.65 GW of EGS supply capacity with lower levelized cost of electricity than conventional hydrothermal and solar photovoltaic projects, respectively. Considering the scenario of flexible geothermal dispatch via wellhead throttling and power plant bypass, these estimates climbed up to 184,112 GW and 44.66 GW, respectively. The majority of EGS supply potential was found in the Western and Southwestern regions of the United States, where California, Oregon, Nevada, Montana, and Texas had the greatest EGS capacity potential. With advanced drilling rates based on state-of-the-art implementations of recent EGS projects, we estimated an average improvement of 25.1% in the levelized cost of electricity. These findings underscored the pivotal role of flexible operations in enhancing the competitiveness and scalability of EGS as a dispatchable renewable energy source.

Pasture Performance: Perspectives on Plant Persistence and Renewal in New Zealand Dairy Systems

Pasture systems dominate the landscape of Aotearoa, New Zealand, and are an integral component of sustainable and resilient livestock production. Predicting the response, performance, and dynamics of pasture species and adapting management practices is key to the long-term economic and environmental sustainability and resilience of the agricultural sector. However, there is limited information on the long-term productivity, performance, and persistence of forage cultivars and species for pasture production systems, particularly when linked to grazing and animal performance. Here, we sought to reduce scientific uncertainty, inform modelling efforts, and contribute to a predictive framework for understanding pasture performance, persistence, and renewal. Inter-annual pasture renewal (direct drilling and cultivation) rates vary by region and year, reflecting both opportunity and problem-based drivers, with the highest pasture renewal rates in Waikato and Canterbury on the North and South Island, respectively.

A Pilot Protection of Negative Sequence and Additional Network Considering Photovoltaic Integration

Background: Introducing pilot protection in active distribution networks containing PV can improve the reliability and selectivity of protection. However, the basic communication facilities of the existing distribution network make it difficult to meet the requirements of data synchronization, and the PV T-connection to the network leads to sudden changes in the impedance angle. Methods: Therefore, pilot protection of a negative sequence and additional network considering PV is proposed. The scheme is based on the feature that the PV model only outputs positive sequence components after a fault. For asymmetrical faults, the negative sequence impedance detected at both ends of the protection is utilized to construct a comparative negative sequence impedance protection criterion. For symmetrical faults, the voltage characteristics of the faulty additional network are utilized to construct a protection criterion. Results: Finally, an actual distribution network model with PV is constructed in PSCAD to verify the effectiveness and reliability of the protection method. Conclusion: The protection method is selective and reliable and is not affected by high penetration rate and PV fault characteristics.

Configuration optimization of a wind-solar based net-zero emission tri-generation energy system considering renewable power and carbon trading mechanisms

Incorporating renewable energy and carbon trading mechanisms within the optimization methods could enhance both the environmental and economic benefits of energy systems. A tri-generation system powered by solar and wind energy is introduced, utilizing solar photovoltaics, wind turbines, and a solar cooling/heating subsystem to attain net-zero carbon emissions via renewable power and carbon trading mechanisms. An improved multi-objective algorithm optimizes the configurations of the energy system across different scenarios. The optimization results demonstrate that the integration of wind turbines, ideally with capacities near 20 MW, lessens the dependence on external power sources and decreases annual expenditure relative to systems relying solely on photovoltaic. Meanwhile, water-cooled chillers are capable of addressing over 88% of the cooling demand, with capacity exceeding 11 MW. Sensitivity analysis highlights that increasing power grid coverage and microgrid penetration rates decrease total costs, while higher building demands reduce economic performance. A new operating mode of net-zero carbon energy systems is provided in the present study.

Experimental study on shale-breaking of special-shaped cutter PDC bit

To enhance the drilling efficiency and extend the service life of PDC (Polycrystalline Diamond Composite) bits in shale formations, this study delves into the rock-breaking mechanisms of special-shaped cutters through a comprehensive experimental approach. This involves optimizing the cutter designs, conducting laboratory experiment and field testing. Among the various cutter geometries considered, concave, axe, planar, and triangular cutters are chosen as the focal points for unit rock-breaking experiments. These tests aim to assess their cutting loads and cutting specific energy to gain a deeper understanding of their performance characteristics. Based on experimental, the debris characteristics are analyzed. Based on the understanding of the shale-breaking characteristics of special-shaped cutters, field testing is performed using a novel PDC bit with a special-shaped cutter. Compared with planar cutters, the concave cutter and the triangular cutter generate lower cutting loads and cutting specific energy. Under identical conditions, the average cutting force and cutting specific energy of concave cutter at different cutting depths are reduced by 16.1% and 19.6% Specifically, the concave cutter generates the largest debris when operated under similar conditions, which is beneficial for increasing rock-breaking efficiency. Laboratory experiment indicate that compared to conventional drill bits, the novel drill bit experiences an increase in torque of approximately 9.8% with increasing WOB (weight on bit). Under high WOB, the ROP (rate of penetration) increases by about 75.4%, while the mechanical specific energy decreases by nearly 40%. Additionally, the novel bit vibration characteristics remain superior to conventional drill bits. Field testing shows that the average ROP of the novel bit and total footage drilled increase by up to 13.3% and 27.2%, respectively, in comparison with those for the conventional bit. The research results are helpful to speed up the efficiency of shale gas drilling.

Evaluation Market Penetration of Infrastructure as A Service (IaaS) to Formulate Marketing Strategy: Study Case Lumos Tech Indonesia

The forecasted revenue growth of cloud computing has become a huge opportunity for IT infrastructure providers, especially for Infrastructure as a Services (IaaS) which have the biggest portion of the cloud computing business. International Data Corporation claims that the estimate revenue for IaaS in 2026 will reach USD 65.5 billion with CAGR 22.8%. Lumos Tech is an alias name that is used to protect the true identity of the firm that is being studied. As a global technology company who provides IT Infrastructure including IaaS offer, ideally Lumos Tech Indonesia should be able to capture this opportunity. However, the company is having a slow penetration rate which approximate to 0.2% for the IaaS offer. It is essential for the company to find factors that hinder the market penetration rate and design a marketing strategy to improve the business performance. The study adopts a mixed methodology where quantitative method is adopted to perform market assessment and the qualitative method focus on assessing the current condition to define the internal factors that hamper market penetration for IaaS offer. The data collection is categorized into two; the external data collection covers the data gathering from outside Lumos Tech through questionnaire, reports and journals and the internal data collection is done by doing an in-depth semi structure interview with the owner of the problem. Furthermore, the analysis is performed by utilizing PESTEL, Porter’s 5 Forces, quantitative descriptive and coding process. The objective of this study is to formulate marketing strategy for Lumos Tech’s IaaS offer by leveraging a modified Business to Business (B2B) marketing mix.

A new model for comprehensively evaluating the economic and environmental effects of vehicle-to-grid(V2G) towards carbon neutrality

Vehicle-to-grid (V2G) technology enables electric vehicles (EVs) to serve as flexible load storage resources, which is expected to play a pivotal role in pursuing carbon neutrality. However, existing studies on the effect of V2G at different stages of carbon neutrality is not sufficient, and there is a lack of discussion on the optimal adoption period for V2G in the context of electricity marketization trading. To fill this gap, a new methodology is proposed in this study to analyze multi-dimension effects of V2G towards carbon neutrality. The model is a novel attempt of applying partial market equilibrium model to depict the interaction between electricity suppliers and V2G adopters. By applying in a China's case, the results demonstrate that: (1) EVs with V2G can substitute 22.2 %–30.1 % energy storage and accelerate the phase-out of coal-fired power. (2) V2G can effectively mitigate electricity price fluctuations, moreover, more fast charging infrastructure will strengthen such effect. (3) V2G only become attractive when renewable energy penetration rate reaches 80 %, otherwise, it cannot effectively reduce the total social cost and carbon emission. (4) In the carbon neutrality scenario with limited emission, the emission reduction effect of V2G is weakened, however, its economic benefit keeps increasing.

Mechanistic investigation on the influence of coating weights on the corrosion behaviour of hot-dip-galvanised Zn-Mg-Al coatings

Time-lapse Microscopy, scanning vibrating electrode technique and potentiodynamic methods were used to study the influence of increasing coating weight (80–310 gm–2) on microstructure, cut-edge and surface corrosion of Zn-Mg-Al coatings in 0.17 M NaCl. Cut-edge corrosion was similar for all coatings due to the oxygen reduction reaction becoming diffusion-limited. A 64% reduction in surface corrosion was observed for high coating weights through increases in eutectic volume fraction. Spatial and temporal corrosion mechanisms were controlled by microstructural morphological differences as coating weight varied. 80 g.m–2 coatings demonstrated lateral anodic spreading potentially reducing coating penetration rates despite their higher surface corrosion rate.

Assessment of the Technical Impacts of Electric Vehicle Penetration in Distribution Networks: A Focus on System Management Strategies Integrating Sustainable Local Energy Communities

Aligned with the objectives of the energy transition, the increased penetration levels of electric vehicles as part of the electrification of economy, especially within the framework of local energy communities and distributed energy resources, are crucial in shaping sustainable and decentralized energy systems. This work aims to assess the impact of escalating electric vehicles’ deployment on sustainable local energy community-based low-voltage distribution networks. Through comparative analyses across various levels of electric vehicle integration, employing different charging strategies and system management approaches, the research highlights the critical role of active system management instruments such as smart grid monitoring and active network management tools, which significantly enhance the proactive management capabilities of distribution system operators. The findings demonstrate that increased electric vehicle penetration rates intensify load violations, which strategic electric vehicle charging management can significantly mitigate, underscoring the necessity of load management strategies in alleviating grid stress in the context assessed. This study highlights the enhanced outcomes derived from active system management strategies which foster collaboration among distribution system operators, demand aggregators, and local energy communities’ managers within a local flexibility market framework. The results of the analysis illustrate that this proactive and cooperative approach boosts system flexibility and effectively averts severe grid events, which otherwise would likely occur. The findings reveal the need for an evolution towards more predictive and proactive system management in electricity distribution, emphasizing the significant benefits of fostering robust partnerships among actors to ensure grid stability amid rising electric vehicle integration.

A mathematical programming approach to export pathway planning of distributed hydrogen production in offshore wind farm

Hydrogen production is a vital development trend to improve the economics and penetration rate of offshore wind farms (OWFs), and distributed hydrogen production (DHP) is a preferred solution for deep and far sea OWFs without expensive submarine cables and offshore substations. The export pathway of OWF-DHP consists of collection pipelines, transmission pipelines, and offshore compressor stations. In this paper, mathematical programming is introduced to explore the export pathway planning problem of OWF-DHP. Firstly, the area of OWF is discretized into multiple grids with the center of the grids being the candidate locations of the offshore compressor station. Then, a binary integer quadratic programming problem is established to optimize both the offshore compressor station location and pipeline construction with different topologies. Further, the mathematical model is solved by the branch and cut algorithm integrated with the proposed dimension reduction methods. Finally, the effectiveness of the proposed export pathway planning approach is verified by the actual data of Baltic Eagle OWF in Germany, which would support the construction of the OWF-DHP project.

Coordinated optimization of configuration and operation of a photovoltaic integrated building cooling system with electricity and ice storages under source-load uncertainties

Solar photovoltaic integration into buildings provides an effective and attractive method to decrease fossil energy consumption and reduce greenhouse gases emission. This study proposes a flexible photovoltaic integrated building cooling system with electricity and ice storages to address the challenges posed by the instability of solar energy and the integration and coordination of multiple components. Uncertainties in solar irradiance, ambient temperature, and cooling load are characterized using a scenario analysis method that combines Latin Hypercube Sampling and the K-Means++ algorithm. Then, aiming to achieve the minimal total cost, including investment, operational, and CO2 emission costs, a two-layer stochastic optimization model is developed to simultaneously determine the optimal capacities and operational strategies for each device. Genetic algorithm and mixed integer linear programming are, respectively, used to solve the two-layer optimization problem. The comparisons between optimum schemes with and without CO2 emission cost demonstrates that when the base chiller’s capacities are 1179 kW and 1081 kW in cases 1 and 2 respectively, it can independently meet 72.37 % and 61.27 % of the cooling load demand throughout the cooling season. In addition, the optimal capacity of photovoltaics, considering CO2 emission, increases by 109.7 %, and its penetration rate reaches 18.3 %, which is 9.7 % higher than the optimal scheme not considering CO2 emission. However, the annualized investment cost increases by 52.3 %. The developed methods provide effective tools for the system design and operation management of solar energy integrated building cooling system.

Effects of the nozzle design parameters on turbulent jet development of active pre-chamber

Active pre-chamber turbulent jet ignition is one of the most promising technologies for developing low- or zero-carbon engines. However, the relevant fundamental studies are far from adequate, particularly for the independent impact of the pre-chamber design parameters on the jet characteristics in the absence of combustion in the main chamber. In this study, the hot turbulent jet characteristics of the pre-chamber fueled with the premixed CH4-air are studied by the double-pass Schlieren imaging. The effects of the pre-chamber nozzle design parameters, including the orifice diameter, total orifice cross-sectional area, and orientation are clarified. The results reveal that the pressure difference between the pre-chamber and main chamber depends on the total orifice cross-sectional area. The effects of the orifice diameter and total orifice cross-sectional area on the penetration rate exhibit a trade-off relation, while the orifice diameter has a more pronounced effect on the hot jet projection area than the total orifice cross-sectional area. Compared to the inclined orifice, the penetration velocity of the straight orifice is faster at the initial hot jet ejection stage. These results are expected to be valuable references for the pre-chamber design and understanding of the ignition mechanisms of active pre-chamber.

A simulation‐based impact assessment of autonomous vehicles in urban networks

AbstractThe behavioural differences between autonomous vehicles (AVs) and human‐driven vehicles (HDVs) can significantly impact traffic efficiency, safety, and emissions. Simulation‐based impact assessments using microscopic traffic models often modify car‐following (CF) and lane‐changing (LC) configurations to differentiate AVs from HDVs. Typically, researchers adjust CF model parameters to replicate AV driving behaviour, but these assumptions can lead to varying conclusions on AV impacts. The scope of each study (e.g., freeways, highways, urban links, intersections) also influences the outcomes. This research conducts an impact assessment utilizing optimized AV driving behavior rather than assumptions on a city network level (Munich) using a simulation‐based platform. The particle swarm optimization (PSO) algorithm is used to calibrate the base model and run simulation experiments under various penetration rates (PRs) and demand scenarios. Results show significant safety improvements throughout the network under higher PRs, while lower PRs might lead to deteriorating safety. At 100% AV PR, the total number of conflicts decreased by around 25% compared to a fully HDV environment. Considering AVs' sensing capabilities, additional safety improvements are found in almost any AV PR. However, AVs might not improve traffic efficiency; in some cases, they may slightly increase average network travel time, though this change is minimal.

Polarization-Accelerated Seawater Splash Simulation for Rapid Evaluation of Protection Performance of an Epoxy Coating on Carbon Steel.

The application of organic coatings is the most cost-effective and common method for metallic equipment toward corrosion, whose anti-corrosion property needs to be improved and evaluated in a short time. To rapidly and rationally assess the anti-corrosion property of organic coatings in the ocean splash zone, a new accelerated test was proposed. In the study, the corrosion protection property of the coating samples was measured by an improved AC-DC-AC test in a simulated seawater of 3.5 wt.% NaCl solution, a simulated ocean splash zone test and a new accelerated test combining the above two tests. The results showed that the corrosion rate of the coating samples was high in the improved AC-DC-AC test, which lost its anti-corrosion property after 24 cycles equal to 96 h. The main rapid failure reason was that the time of the water and corrosive media arriving at the carbon steel substrate under the alternating cathodic and anodic polarization with symmetrical positive and negative electric charges was shortened. The entire impedance of the coating samples was improved by about 1.6 times more than that in the initial early time in the simulated ocean splash zone test, which was caused by the damage effect from the salt spraying, drying, humidifying, salt immersion, high temperature and UVA irradiation being weaker than the enhancement effect from the post-curing process by the UVA irradiation. In the new accelerated test, the samples lost their corrosion resistance after 12 cycles equal to 288 h with the fastest failure rate. On account of the coupling process of the salt spraying, drying, humidifying, salt immersion, high temperature combined with the cathodic and anodic polarization and the UVA irradiation, the penetration and transmission rate of water and corrosive media in the coating were further accelerated, the corrosion rate on the carbon steel substrate was reinforced even larger and the destruction of the top polymer molecules was more serious. The new accelerated test showed the strongest damage-acceleration effect than that in the other two tests.

Penetration state recognition for tungsten inert gas welding via an alternating cusp-shaped magnetic field-assisted molten pool-oscillation

To ensure optimal penetration in direct current (DC) argon tungsten arc welding, a method was proposed to recognize the molten pool penetration during molten pool oscillation under alternating cusp-shaped magnetic field (ACSMF). An arc discharge model is established to analyze the oscillation mechanism of the molten pool under ACSMF. The periodic variation of arc shape induces the periodic oscillation to establish a mapping relationship with the fluctuation of arc voltage waveform. At the excitation current of 3 A and frequency of 10 Hz, the arc voltage waveform undergoes abrupt changes at 1.26 V and 1.37 V, corresponding to the critical and the full penetration states, respectively. The errors in identifying moving penetration are 0.8 % and 0.7 %, with a full penetration weld, demonstrating a penetration rate of 100 %, indicating effective penetration recognition. Arc sensing technology for tungsten inert gas (TIG) welding under ACSMF is poised for gradual application in single-side welding and double-side forming of medium and thick plates. It is anticipated to evolve towards real-time identification technology for molten pool penetration monitoring.

A Generalized Load Model Considering the Fault Ride-Through Capability of Distributed PV Generation System

Considering the voltage stability problem brought by large-scale distributed PV access to the distribution network, this paper proposes a generalized load model that considers the fault ride-through capability of distributed PV. Firstly, the detailed model of the distribution network is established, and the detailed model is calibrated based on the measured data, the simulation errors are below 1%. And then establish a generalized load model considering distributed PV high and low voltage traversal ability. The sensitivity analysis results are used to rank the parameters to be identified, and the parameters with higher sensitivity are identified. The parameters are obtained from the detailed model and measured data, and four sets of parameters are identified and simulated under different PV penetration rates and fault conditions. The calculated fitting errors are less than 1%. The results show that the generalized load gray box model of the distribution network with distributed PV high and low voltage ride-through capability can reflect the dynamic characteristics of the distribution network well.

Transforming Oil Well Drilling: Prediction of Real-Time Rate of Penetration with Novel Machine Learning Approach in Varied Lithological Formations

Transforming Oil Well Drilling: Prediction of Real-Time Rate of Penetration with Novel Machine Learning Approach in Varied Lithological Formations