High Volume Capacity Research Articles

A simulation-based approach to analysing delays in the transport of critically ill neonates

ABSTRACT Neonatal interfacility transport ensures that critically ill neonatal patients can receive higher levels of care when needed. Delays in the transport process impact the quality of care and increase the risk of medical complications. The objective of this study is to investigate the operations-related factors that contribute to transport delays and explore the role of discrete-event simulation in improving the transport process. Semi-structured interviews were conducted with stakeholders to understand the neonatal interfacility transport process. Analysis of historical call logs and transport data was performed to identify inputs to the discrete-event simulation model. Statistical tests were used to identify the effect of various factors on wait time and transport time in the simulation model. High patient volume and limited bed capacity at the receiving hospitals are identified as bottlenecks that lead to extended wait time and transportation time. Additionally, having more geographically distributed ambulance resources does not significantly help with the time delays when the receiving hospital capacity stays unchanged. Discrete-event simulation models can be used to investigate the effects of operations-related factors in the interfacility transport of critically ill neonates to support future process improvement.

Two-dimensional metallic Be2Al monolayer as a potential anode material for lithium-ion/sodium-ion batteries

Developing anode materials that combine excellent robustness, high-volume capacity, and superior electrical conductivity is essential for advancing high-performance ion batteries. Through comprehensive first-principles calculations, this paper illustrates the possibility of a two-dimensional Be2Al monolayer as an anode candidate for lithium/sodium-ion batteries. The Be2Al monolayer exhibits a high theoretical energy storage capacity (2382/2382 mAh/g for Li/Na) and an ultra-low diffusion barrier (124/77 meV for Li/Na). Its average open-circuit voltage (0.35/0.52 V for Li/Na) falls within the desired ideal range. Additionally, the Be2Al monolayer demonstrates excellent electrical conductivity, facilitating efficient electron transport. These promising outcomes indicate that the Be2Al monolayer can be an effective anode for next-generation lithium-ion and sodium-ion batteries.

Designing a Se-intercalated MOF/MXene-derived nanoarchitecture for advancing the performance and durability of lithium-selenium batteries

Lithium-selenium batteries have emerged as a promising alternative to lithium-sulfur batteries due to their high electrical conductivity and comparable volume capacity. However, challenges such as the shuttle effect of polyselenides and high-volume fluctuations hinder their practical implementation. To address these issues, we propose synthesizing Fe-CNT/TiO2 catalyst through high-temperature sintering of an amalgamated nanoarchitecture of carbon nanotubes decorated metal–organic framework (MOF) and MXene, optimized for efficient selenium hosting, leveraging the distinctive physicochemical properties. The catalytic features inherent in the porous Se@Fe-CNT/TiO2 nanoarchitecture were instrumental in promoting efficient ion and electron transport, and lithium-polyselenide kinetics, while its inherent porosity could play a crucial role in inhibiting electrode stress during cycling. This nanoarchitecture exhibits remarkable battery performance, retaining 99.7% of theoretical capacity after 425 cycles at 0.5 C rate and demonstrating 95.8% capacity retention after 2000 cycles at 1 C rate, with ∼100% Coulombic efficiency. Additionally, the Se@Fe-CNT/TiO2 electrode exhibited an impressive recovery of 297.5 mAh/g (97.9%) capacity after undergoing 450 cycles at a charging rate of 10 C and a discharging rate of 1 C. This synergistic integration of MOF- and MXene-derived materials unveils new possibilities for high-performance and durable LSeBs, thus advancing electrochemical energy storage systems.

Phase-field simulation of interface growth of magnesium metal anodes during electrodeposition

Mg-metal has abundant reserves and extremely high-volume capacity, making it an excellent choice as the negative electrode for low-cost, high-volume energy-density batteries. More and more studies have shown that there is still a problem of dendritic growth in Mg-metal. Here, we use the open-source MOOSE software package to establish a phase-field model for Mg-electrodeposition and study the dynamic morphological evolution of the growth of Mg-metal anode interfaces under different overpotentials in two dimensions. By studying the temporal-spatial distributions of ion concentration, chemical potential, and electric potential, we analyze the growth processes of Mg-metal anode interfaces under different applied overpotentials in detail. The results show that the Mg-metal anode interfaces only grow dendrites under applied overpotentials ranging from −0.24 to −0.30 V because the interface electrochemical reactions rate is greater than the interface ion transfer rate.

ADSORPTION OF Cu (II) IONS FROM WASHING SOLUTIONS OF TAILINGS BY DOWEX MAC-3 H+ SORBENT

In this article, the experimental results of the adsorption of Cu2+ ion with Dowex Mac-3H+, a cation exchange resin with weak acid character, were investigated. Factors affecting the adsorption of copper ions from sulfated solutions: the initial concentration of Cu2+ ion, the dose amount of the adsorbent, the concentration-time, and the pH of the solution were studied. The obtained results showed that Dowex Mac-3H+ resin shows a high volume capacity (322.6 mg/g) in the separation of Cu2+ ions from sulfated solutions. At the initial concentration of 0.5 g/l, for 4 hours, when 0.2 g of sorbent was taken, at pH 6, at room temperature, the adsorption rate of Cu2+ ions was maximal (98%). In the first 1 hour, sorption occurs at a high rate, and increasing the contact time does not affect the process much. Due to the increase in the concentration of OH- ions at higher pH values, it is observed that the Cu2+ ion changes to the Cu(OH)2 precipitate form. The values of the obtained experimental results fully correspond to the Langmuir and Freundlich isotherms. It can be seen from the adsorption isotherms of the Langmuir and Freundlich model that the adsorption of Cu2+ ions on the resin occurs according to the chemisorption mechanism

CoSe2-decorated carbon nanofibers: A catalytic electrode for uniform Li2Se nucleation in lithium-selenium batteries

Selenium cathodes have attracted widespread attention due to their high electronic conductivity and considerable volume capacity. However, the harmful shuttle of lithium polyselenides and irregular deposition of lithium selenide (Li2Se) severely degrade the redox rate of active selenium, causing poor cycling stability. Toward overcoming these limitations, herein, a catalytic electrode based on carbon nanofibers loaded with CoSe2 nanoparticles (CoSe2@CNF) is designed and engineered to trap polyselenides and activate their conversion. Density functional theory (DFT) calculations show that the introduction of CoSe2 nanoparticles lowers the redox barrier for Li2Se growth. Even more important, the presence of a homogeneous distribution of CoSe2 provides abundant nucleation sites for uniform Li2Se deposition. As a result, Li-Se batteries based on Se/CoSe2@CNF free-standing electrodes exhibit outstanding cycle stability. After 800 cycles, Se/CoSe2@CNF electrodes display a high capacity of 435.1 mAh g−1 with a 0.032% capacity decay per cycle at 0.5C. Even at a selenium loading of 4.1 mg cm−2, a high capacity retention rate of 72.8% is measured. Overall, this work provides a new strategy for achieving high-performance Li-Se batteries by introducing efficient polyselenide electrocatalysts as selenium hosts to facilitate the conversion of polyselenides and regulate the homogenous growth of Li2Se.

Nanoflowers-like LiTi2(PO4)3 on carbon nanotube fibers as novel binder-free anodes for high-performance fiber-shaped aqueous rechargeable lithium-ion batteries

NASICON-type LiTi2(PO4)3 (LTP) shows tremendous potential for applications in aqueous rechargeable lithium-ion batteries (ARLIBs) due to its three-dimensional open-framework and flat voltage platform. Unfortunately, conventional solid-phase reactions and high-temperature calcination methods are unable to meet the demand for self-standing electrodes for flexible wearable ARLIBs. Herein, we develop a simple and effective one-step solvothermal method to grow nanoflowers (NFs)-like LTP directly on carbon nanotube fibers (CNTFs) as binder-free anodes for fiber-shaped ARLIBs (FARLIBs) without additional high-temperature treatment. Benefitting from the robust adhesion of the active material to the substrate and binder-free feature, the prepared LTP NFs/CNTF anode provides a high reversible volume capacity of 85.2 mAh cm−3 at a current density of 0.4 A cm−3. The quasi-solid-state FARLIB is successfully assembled by binder-free cathode coupling with LiMn2O4 nanowall arrays directly grown on CNTF, achieving a high capacity of 58.3 mAh cm−3 at a current density of 0.4 A cm−3 and exhibiting an encouraging 92.3 mWh cm−3 maximum energy density. This work provides an effective strategy for the design of novel binder-free electrodes for next-generation wearable FARLIBs.

Integrated silicon photonic MEMS

Silicon photonics has emerged as a mature technology that is expected to play a key role in critical emerging applications, including very high data rate optical communications, distance sensing for autonomous vehicles, photonic-accelerated computing, and quantum information processing. The success of silicon photonics has been enabled by the unique combination of performance, high yield, and high-volume capacity that can only be achieved by standardizing manufacturing technology. Today, standardized silicon photonics technology platforms implemented by foundries provide access to optimized library components, including low-loss optical routing, fast modulation, continuous tuning, high-speed germanium photodiodes, and high-efficiency optical and electrical interfaces. However, silicon’s relatively weak electro-optic effects result in modulators with a significant footprint and thermo-optic tuning devices that require high power consumption, which are substantial impediments for very large-scale integration in silicon photonics. Microelectromechanical systems (MEMS) technology can enhance silicon photonics with building blocks that are compact, low-loss, broadband, fast and require very low power consumption. Here, we introduce a silicon photonic MEMS platform consisting of high-performance nano-opto-electromechanical devices fully integrated alongside standard silicon photonics foundry components, with wafer-level sealing for long-term reliability, flip-chip bonding to redistribution interposers, and fibre-array attachment for high port count optical and electrical interfacing. Our experimental demonstration of fundamental silicon photonic MEMS circuit elements, including power couplers, phase shifters and wavelength-division multiplexing devices using standardized technology lifts previous impediments to enable scaling to very large photonic integrated circuits for applications in telecommunications, neuromorphic computing, sensing, programmable photonics, and quantum computing.

Ultra-stable sandwich shaped flexible MXene/CNT@Ni films for high performance supercapacitor

MXene exhibits high volume capacity, but poor flexibility and mechanical properties have seriously limited its further applications. To address this issue, a sandwich shaped flexible MXene/CNTs@Ni film has been fabricated via a simple filtration approach, wherein the nickel-electroless plating on CNTs (CNTs@Ni) are utilized as the effective interlayer spacers of MXene nanosheets to stabilize their layer structures. In addition, the optimized MXene/CNTs@Ni film electrode as a binder-free and self-supported electrode exhibits robust mechanical stability and impressive electrochemical properties, especially with a high specific capacitance of 990.8 F cm−3, about 1.4 times and 2.4 times higher than that of MXene/CNTs film electrode and pristine MXene film electrode, respectively. A flexible symmetrical supercapacitor (FSMS) was constructed based on MXene/CNTs@Ni film. Notably, the FSMS owns a high energy density of 14.5 Wh kg−1, a high power density of 2571.4 W kg−1, and a good cycling stability, suggesting its potential application in portable energy technologies.

Crocus sativus (L.) Grown in Pots with High Volume Capacity: From a Case of Study to a Patent

Saffron (Crocus sativus L.) cultivation is widespread in different parts of the world, including various Mediterranean areas. The crop management techniques, requiring intensive manual labor from planting, weeding, flower picking to the collecting of stigmas, contribute greatly to the high price of the spice. Traditionally, the corms are cultivated in field soil and only stigmas are collected to obtain the spice while the flower’s remaining parts, corresponding to about 90% of the total biomass, are discarded and thrown away. In this study, in order to overcome some difficulties occurring during the whole crop cycle (pathogens, fungi, pests, weeds, etc.), as well as to ease and increase floral bioresidue recovery, an alternative planting way for Crocus sativus L. was proposed relying on the use of large pots. For this aim, corms with 3.0–3.5 cm diameter size, from two different geographical origins (Spain, Holland), were planted in plastic pots with a volume of 250 L or 350 L, placed in two different areas of the Basilicata region (Italy). The effect of this new growing condition on dry stigma yield as well as daughter corm yield and size was evaluated. Although this cultivation system is more expensive than the traditional one, it offers numerous and huge advantages. Among them, it allows us to maintain a more correct posture and to preserve flower integrity during harvesting. The structural integrity of the tepals is a very important factor to obtain innovative dried flowers in their original tridimensional shape (3D). Consequently, the proposed cultivation system facilitates the achievement of a real “niche product” with high added value (absence of pollen grains). Moreover, the qualitative analysis of the spice, performed according to the International Standardization Organization Normative 3632 (ISO 3632-2/1:2010/2011), classified all investigated saffron samples in the first qualitative category. The results of the first three trial years are very exciting and promising as they are similar to those from the literature carried out in ground soil. However, corms from Spain gave the best results. Further investigations are in progress in order to optimize this alternative cultivation system.

Efficient Sodium Storage in Selenium Electrodes Achieved by Selenium Doping and Copper Current Collector Induced Displacement Redox Mechanisms

AbstractSelenium (Se), with its high specific volume capacity and high electronic and superior kinetics, is considered a promising electrode material with promising applications. However, the solvation and shuttle effects of polyselenides hinder their further application. The selenium/nitrogen‐doped hollow porous carbon spheres (Se/NHPCs) are obtained using the sacrificial template and in situ gas‐phase selenization methods. The Se species are doped into carbon matrixes in an adjustable amount to form Se‐C(N) bonds during this process. Density functional theory calculations show that the Se‐C(N) bond enhances the charge transfer between Na2Se and carbon matrix and binding energy, which improves rate performance and cycling stability. As expected, Se/NHPCs electrode exhibit high reversible capacity (480 mAh g–1 at 0.5 A g–1 after 200 cycles) and rate performance (311 mAh g–1 at 5 A g–1) as the anode for sodium‐ion batteries. A series of ex situ characterization results show that Cu2Se produced by copper current collector induction is effective in the adsorption of polyselenides while enhancing the electrode conductivity. Since the lattice structures of Cu2Se and Na2Se are similar, this displacement reaction that does not involve lattice reconfiguration provides an effective strategy for the preparation of high‐performance and low‐cost electrode materials.

Realizing highly reversible and deeply rechargeable Zn anode by porous zeolite layer

Aqueous zinc-ion batteries are of high interest due to their intrinsic safety, low cost, and high volume capacity. However, entrenched problems such as the dendrite growth and complex side reactions of zinc metal anodes severely reduce the reversibility of the battery. In this work, the modified porous natural zeolite materials are used to prepare a protective coating layer for the zinc anode. Such coating layer has a positive effect on inhibiting side reactions associated with dendrites as confirmed by test results. As a consequence, the modified zinc metal anodes can operate over 1200 h at 1 mA cm −2 with 0.5 mAh cm −2 in symmetric cells and achieve a lifespan up to 500 h at an ultrahigh areal capacity of 30 mAh cm−2 (10 mA cm−2 for 3 h). The full cells using modified Zn anodes and the V10O24-PANI nanosheet cathodes deliver a capacity of 332 mAh g−1 at 1 A g−1 and also show great cycling stability with 89% retained capacity after 1000 cycles at 10 A g−1. By solving the electrochemical problems of zinc anodes, the proposed strategy provides a new opportunity for the widespread applications of high-performance aqueous batteries in next-generation energy storage systems.

Properties of Fe-Si Alloy Anode for Lithium-Ion Battery Synthesized Using Mechanical Milling.

Silicon (Si)-based anode materials can increase the energy density of lithium (Li)-ion batteries owing to the high weight and volume capacity of Si. However, their electrochemical properties rapidly deteriorate due to large volume changes in the electrode resulting from repeated charging and discharging. In this study, we manufactured structurally stable Fe–Si alloy powders by performing high-energy milling for up to 24 h through the reduction of the Si phase size and the formation of the α-FeSi2 phase. The cause behind the deterioration of the electrochemical properties of the Fe–Si alloy powder produced by over-milling (milling for an increased time) was investigated. The 12 h milled Fe–Si alloy powder showed the best electrochemical properties. Through the microstructural analysis of the Fe–Si alloy powders after the evaluation of half/full coin cells, powder resistance tests, and charge/discharge cycles, it was found that this was due to the low electrical conductivity and durability of β-FeSi2. The findings provide insight into the possible improvements in battery performance through the commercialization of Fe–Si alloy powders produced by over-milling in a mechanical alloying process.

Mn-doped K0.23V2O5 nanobelts as cathode materials for high performance flexible all-in-one zinc ion batteries

A tremendous amount of work is devoted to build an all-in-one energy storage equipment to meet the ever-increasing demand for flexible wearable electronics. At present, the flexible all-in-one zinc ion batteries have captured enormous attention owing to its high volume capacity, abundant reserve and robust security. Herein, the Mn-doped K 0.23 V 2 O 5 nanobelts materials are innovatively prepared by introducing Mn and K ions into vanadium oxide, which will acquire an intensive conductivity and favorable Zn 2+ storage. In the conventional aqueous zinc ion batteries, the Mn-doped K 0.23 V 2 O 5 electrode offers a high discharge capacity of 269.1 mAh g −1 after 100 cycles at the moderate current density of 1.0 A g −1 and a remarkable cyclability (226.7 mAh g −1 after 5000 cycles at 10.0 A g −1 ). Moreover, the electrode also displays a good rate performance. Besides, the binder-free Mn-doped K 0.23 V 2 O 5 /CNT film is further constructed for flexible all-in-one batteries, which exhibits satisfactory cycling performance with high-capacity retention of greater than 84.1% after 2000 cycles under continuous bending. Thus, this work provides a facile strategy for new-generation convenient and wearable energy-storage facility. • An efficient Mn, K co-doping strategy to synthesize Mn-KVO hybrid cathode. • The Mn-KVO-1:2 electrode delivers high specific capacity and good rate performance. • Flexible pliable Mn-KVO-1:2/CNT hybrid films were prepared. • A novel flexible all-in-one battery is designed and prepared.

Slopping index for LD converters based on sound and image data fusion by fuzzy Kalman filter

ABSTRACT The LD (Linz Donawitz) steelmaking process is the most used in the steel industry due to its high-volume capacity and low cost per ton of steel produced. However, the basic oxygen steelmaking process in LD converters is subjected to potential steel charge overflows, often called ‘slopping’. Besides yield losses, slopping events can damage the environment and expose employees to danger. More than ever, steelmaking plants need to avoid this type of event to keep producing as environmental impacts are no more tolerable by society. Steelmaking plants already use different methods to monitor and detect slopping events, but they are often limited and unreliable. Therefore, this paper proposes a multi-sensor data fusion process to generate a reliable slopping index to warn operators of potential slopping events and detect the triggered ones. The work is based on sound and image data (67 heats with 27 slopping events) collected on previous trials at a 350-ton LD converter. The Kalman filter was applied as a data fusion agent of two indexes, one resulted from computer vision analysis of the LD converter mouth (image data), the other resulted from digital signal analysis of sound captured on the converter’s hood (sound data). Fuzzy sets were applied for adaptative tuning of the Kalman filter to improve the data fusion process. Besides the increase of alarm accuracy and heat classification, the data fusion index worked better on different scenarios and produced a more reliable indicator for a slopping prevention system.

Capacity increasing of arterial streets with controlled motion

The problem of capacity increasing of arterial streets with controlled motion is investigated in this paper. For investigation, sections between intersections on the road network of Lviv city were chosen at their different length and roadway width with most saturated traffic. Methods of capacity increasing of arterial streets with controlled motion and factors that have impact on the capacity reduction are analyzed. Capacity of intersections at different volume-capacity ratios is determined. The distribution of average speed for sections between intersections of different length is built. It is established that on sections of medium length between signalized intersections and the high volume-capacity ratio, the speed of traffic flow does not reach maximum values. It is possible to increase the speed and the capacity of sections between intersections by increasing their length, sufficient for flow acceleration to the maximal constant speed and further braking before the intersection. To determinate the recommended speed of movement on arterial directions, road conditions are taken into account, which are formed with simultaneous impact of several factors: volume-capacity ratio of intersection in braking zone, volume-capacity ratio of intersection in acceleration zone, the number of lanes, the length of the section between intersections and the average speed of the traffic flow. It is determined that the average speed of traffic flow on short sections between intersections (the length less than 300 m) is 27 – 33 km/h, on sections of medium length – 35 – 38 km/h/ Such speed will allow to traffic flow reaching the line of constant movement in given road conditions. Conducted research allows taking into account road traffic conditions while justifying the calculating speed of traffic flow, in result of which capacity of arterial streets of controlled motion increases.

Intramolecular hydrogen bonds induced high solubility for efficient and stable anthraquinone based neutral aqueous organic redox flow batteries

Solubility of redox active materials (RAMs) is key to realize high volume capacity and energy density in aqueous organic redox flow batteries (AORFBs). In anthraquinone (AQ)-based RAMs, hydrophilic groups substituted at β-sites (2,3,6,7) are expected to improve water-miscibility much better than α-sites (1,4,5,8). In this work, we find an anomalous case: 3-((9,10-dioxo-9.10-dihydroanthracen-2-yl)amino)-N,N,N-trimethylpropan-1-aminium chloride (2-DPAQCl) functioned with the hydrophilic groups surprisingly exhibits poor solubility with less than 0.05 M, however its isomer 3-((9,10-dioxo-9,10-dihydroanthracen-1-yl)amino)-N,N,N-trimethylpropan-1-aminium chloride (1-DPAQCl) shows high solubility at 1.44 M in water. The results from 1H nuclear magnetic resonance (NMR) and infrared (IR) spectra suggest that intermolecular hydrogen bonds (HBs) are formed between N–H donors and Cl− acceptors in 2-DPAQCl, which is different from the case for 1-DPAQCl that N–H donors interact with neighboring CO acceptors as intramolecular HBs. Benefited from the intramolecular HBs, water is prone to break the interaction between solute molecules than that in 2-DPAQCl, leading to better water-solubility. Electrochemical investigations indicate that the peak-to-peak separations ΔEpp of 1-DPAQCl is very narrow in unbuffered aqueous solution as well as in buffered aqueous solution at pH 7.0, implying its highly electrochemical reversibility and facile reaction kinetics, which further indicates 1-DPAQCl is suitable to serve as a negative RAM for neutral AORFBs.

A high-capacity of oxygen induced SrTiO3 cathode material for rechargeable Alkaline Zinc battery

The tremendously usage in batteries has led to development of safe, economical and environment friendly batteries. Therefore, the progress to explore new type of battery such as rechargeable alkaline zinc batteries (RAZBs) based on metal oxides has attracted many interests. In this study, RAZBs based on SrTiO3 nanoparticles as cathode is successfully produced and also managed to generate high specific volume capacity of 387 mAh cm−3 at 1.2 V. Based on the total volume of battery, the energy density of the battery is 37 mWh cm−3. The SrTiO3 prepared via facile hydrothermal process exhibits large specific surface area. Besides the surface area, the presence of oxygen vacancies (Vo¨) in SrTiO3 is also contributed to the high electron contact efficiency. The presence of Vo¨ play an important role in the redox property and rechargeability of SrTiO3 as cathode. The RAZBs based on SrTiO3 nanoparticles shows a good cycling performance and achieve 100% coulombic efficiency. In conclusion, the new cathode material based on SrTiO3 create new possibilities for RAZBs.

Plasma Technology: An Ultimate Solution for Solid Waste Management

The growth of the population is related to urbanization, development, and industrialization. There found a strong correlation between population, industrialization, and waste production. The famous thermodynamics laws offer insights into the technological/marketing impact on waste production and energy conversion processes. The conventional methods such as land filling, combustion, gasification, incineration, etc. not enough to manage such a huge volume of waste. The non-segregation tendency, consumerism nature makes this waste management work problematic. The paper studies the natural efficiency in the waste management system and also the inability of traditional technology's to handle rapidly increasing waste volume. The plasma-based waste technology is similar to the natural waste management cycle, but with high volume capacity in a short duration. This also has a scope of waste to energy (WtE) conversion. Though plasma has high installation and maintenance costs, revenue generation from byproducts like syngas and slag will create it financially viable.

A MOF-derived carbon host associated with Fe and Co single atoms for Li–Se batteries

Lithium–selenium (Li–Se) batteries are considered a promising energy storage material due to their high electronic conductivity and volume capacity.