Small Volume Change Research Articles

Three-dimensional volume and shape of the infrapatellar fat pad during quasi-static knee extension from 30° to 0°: comparisons of patients with osteoarthritic knees and young, healthy individuals.

[Purpose] Previous studies suggest that the infrapatellar-fat-pad is affected by aging or knee osteoarthritis, and that the infrapatellar-fat-pad in knee osteoarthritis cases may be associated with limited mobility during knee movement. This study aimed to determine changes in the shape and volume of the infrapatellar-fat-pad between 30° and 0° of knee extension in knee osteoarthritis cases and in young, healthy individuals, and to characterize differences in patellar mobility, patellar tendon mobility, and length between the groups. [Participants and Methods] We created 3D models of the infrapatellar-fat-pad, the patellar tendon, and bones using sagittal MRI with the knee at 30° and 0°. The following four parameters were determined: (1) movement of the infrapatellar-fat-pad; (2) infrapatellar-fat-pad volume; (3) angle and surface length of the patellar tendon; and (4) patellar movement. [Results] Compared with the knee osteoarthritis group, the healthy group showed (1) reduced anterior movement of the infrapatellar-fat-pad; (2) smaller volume changes only in the infero-postero-lateral portion; and (3) no changes in the angle of the patellar tendon to the tibial plateau between 30° to 0°. [Conclusion] In conclusion, between 30° and 0°, (1) the infrapatellar-fat-pad in patients with knee osteoarthritis exhibited less anterior movement, and (2) the patellar tendon angle was diminished in patients with knee osteoarthritis compared with those of young-healthy knees.

3D all boron based porous topological metal for Mg- and Al-ion batteries anode material: A first principle study

Mg-ion batteries and Al-ion batteries are considered as potential replacements for Li-ion batteries due to their high-volumetric-capacity. The search for high-performance anode materials with a fast and reversible insertion of Mg/Al-ions remains a major challenge. In this study, the potential applications of a 3D topological metal boron structure (H-boron) as anode materials for MIBs/AIBs have been studied using the first-principle method. Their ultrahigh maximum capacities are 2480 and 5114 mAh/g for Mg/Al with small volume changes. The diffusion barriers are 0.34 and 0.35 eV for Mg/Al in H-boron. Above results demonstrate that H-boron can be a promising MIBs/AIBs anode.

Engineering Transition Metal Layers for Long Lasting Anionic Redox in Layered Sodium Manganese Oxide

AbstractOxygen‐redox‐based‐layered cathode materials are of great importance in realizing high‐energy‐density sodium‐ion batteries (SIBs) that can satisfy the demands of next‐generation energy storage technologies. However, Mn‐based‐layered materials (P2‐type Na‐poor Nay[AxMn1−x]O2, where A = alkali ions) still suffer from poor reversibility during oxygen‐redox reactions and low conductivity. In this work, the dual Li and Co replacement is investigated in P2‐type‐layered NaxMnO2. Experimentally and theoretically, it is demonstrated that the efficacy of the dual Li and Co replacement in Na0.6[Li0.15Co0.15Mn0.7]O2 is that it improves the structural and cycling stability despite the reversible Li migration from the transition metal layer during de‐/sodiation. Operando X‐ray diffraction and ex situ neutron diffraction analysis prove that the material maintains a P2‐type structure during the entire range of Na+ extraction and insertion with a small volume change of ≈4.3%. In Na0.6[Li0.15Co0.15Mn0.7]O2, the reversible electrochemical activity of Co3+/Co4+, Mn3+/Mn4+, and O2‐/(O2)n‐ redox is identified as a reliable mechanism for the remarkable stable electrochemical performance. From a broader perspective, this study highlights a possible design roadmap for developing cathode materials with optimized cationic and anionic activities and excellent structural stabilities for SIBs.

Oxyfluoride Cathode for All-Solid-State Fluoride-Ion Batteries with Small Volume Change Using Three-Dimensional Diffusion Paths

All-solid-state fluoride-ion batteries (FIBs) are expected to become the next generation of battery systems owing to their outstanding energy storage characteristics. However, the volume expansion of the cathode that accompanies the insertion of fluoride ions remains an urgent issue to be addressed. Even if an intercalation-type cathode is applied in FIBs, fluoride-ion insertion into the interstitial sites of two-dimensional materials such as LaSrMnO4 still leads to non-negligible volume expansion. Here, we report a novel intercalation-type material, Sr3Fe2O5F2, possessing the Ruddlesden–Popper structure as a cathode material for FIBs that features not only interstitial sites but also anion vacancies as three-dimensional (3D) percolation sites to accommodate fluoride ions. This material exhibits a relatively high capacity of 118 mAh g–1 and good cycling stability over 70 cycles. Fe2+/Fe3+ redox reactions are responsible for charge compensation during the charging and discharging processes. The crystal structure during the charging process changes from Sr3Fe2O5F0.46 to Sr3Fe2O5F2 by using the 3D percolation sites with an extremely small volume change of approximately 0.17% and thereafter changes to Sr3Fe2O5F3 with a P4/mmm symmetry by using interstitial sites with a large volume change of approximately 11%. Our findings should pave the way for the design of new cathodes with excellent cycling stability and minimal volume expansion based on the percolation mechanism.

Elucidating the Synergic Effect in Nanoscale MoS2 /TiO2 Heterointerface for Na-Ion Storage.

Interface engineering in electrode materials is an attractive strategy for enhancing charge storage, enabling fast kinetics, and improving cycling stability for energy storage systems. Nevertheless, the performance improvement is usually ambiguously ascribed to the "synergetic effect", the fundamental understanding toward the effect of the interface at molecular level in composite materials remains elusive. In this work, a well-defined nanoscale MoS2 /TiO2 interface is rationally designed by immobilizing TiO2 nanocrystals on MoS2 nanosheets. The role of heterostructure interface between TiO2 and MoS2 by operando synchrotron X-ray diffraction (sXRD), solid-state nuclear magnetic resonance, and density functional theory calculations is investigated. It is found that the existence of a hetero-interfacial electric field can promote charge transfer kinetics. Based on operando sXRD, it is revealed that the heterostructure follows a solid-solution reaction mechanism with small volume changes during cycling. As such, the electrode demonstrates ultrafast Na+ ions storage of 300 mAh g-1 at 10 A g-1 and excellent reversible capacity of 540 mAh g-1 at 0.2 A g-1 . This work provides significant insights into understanding of heterostructure interface at molecular level, which suggests new strategies for creating unconventional nanocomposite electrode materials for energy storage systems.

Dense T-Nb2O5/Carbon Microspheres for Ultrafast-(Dis)charge and High-Loading Lithium-Ion Batteries.

Orthorhombic niobium pentoxide (T-Nb2O5) is regarded as a potential anode material for lithium-ion batteries (LIBs) due to ultrafast charge/discharge and high safety. However, the poor electronic conductivity and low mass loading of nanostructured T-Nb2O5 limit its practical application in LIBs. Herein, we design and construct dense microspheres consisting of nanostructured T-Nb2O5 embedded in amorphous N-doped carbon (Nb2O5@NC) via a facile method to achieve fast ionic and electronic transport as well as a high mass loading. The dense micro-sized particles with an interconnected carbon network avoid the low mass loading and volumetric energy density of conventional nanostructures. Interconnected pores in the range of a few nanometers are also formed in the Nb2O5@NC microspheres. Notably, at a high mass loading of 12.8 mg cm-2, Nb2O5@NC can achieve a high specific capacity of 171.5 mAh g-1 and an areal capacity of 2.05 mAh cm-2, showing its high lithium storage capacity. The intercalation reaction mechanism with a small volume change during cycling at both crystal lattice and microsphere levels is confirmed by in situ X-ray diffraction and in situ high-resolution transmission electron microscopy. The elegant structure and the electrochemical reaction mechanism disclosed in the work is important for designing ultrafast-(dis)charge electrode materials.

PHP-graphene nanoribbon-assembled porous metallic carbon for sodium-ion battery anode with high specific capacity

In recent years, a number of three-dimensional (3D) porous metallic carbon allotropes have been proposed to be used as anode materials for metal-ion batteries by assembling graphene or penta-graphene nanoribbons. Here, based on density functional theory and tight-binding model, we design a new 3D porous metallic carbon monolith (termed Hex-C568) consisting of PHP-graphene nanoribbons which contain pentagonal, hexagonal and octagonal rings. It is thermally, dynamically and mechanically stable. We find that its metallicity is attributed to the delocalized electrons in the p-orbitals of the sp2 hybridized carbon atoms, and Hex-C568 is a promising anode material for Na-ion batteries with high performance. Its reversible gravimetric and volumetric capacities are 787.53 mAhg−1 and 718.10 mAhcm−3, respectively, with low diffusion energy barrier (0.04–0.30 eV), low average open-circuit voltage (0.26 V), and small volume change during the charging/discharging process (3.71%). These electrochemical properties are superior to those of most recently reported anode materials, suggesting that PHP-graphene nanoribbon is a promising building unit for the design of novel carbon anode materials going beyond graphene and penta-graphene.

Highly cycle-stable and robust reversible protonic ceramic cells with air electrode supported structure enabled by single-step co-firing and infiltration

Due to the well-matched thermal expansion coefficient and small volume change, air electrode supported reversible protonic ceramic cells (AS-RePCCs) look promising in cyclic stability. In this work, AS-RePCCs are successfully fabricated at 1220 °C for the first time using the single-step co-firing technique. A tightly integrated interface and enriched proton migration network are created between the hydrogen electrode and electrolyte, which effectively promote the proton transfer and alleviate hydrogen partial pressure at the interface, enhancing the performance and stability of the cell. To further optimize the performance, nano La0.6Sr0.4CoO3 (LSC) particles are deposited into the air electrode matrix via infiltration. At 700 °C, the cell with 1.2 wt% LSC shows the maximum power density of 227 mW cm−2 and the current density of 543 mA cm−2 and 1113 mA cm−2 at 1.3 V and 1.5 V, respectively. More significantly, the performance remains stable during more than 60 rapid reversible cycles with a rate of one cycle every 2 h, followed by 30 deep thermal cycles (between 700 and 300 °C), demonstrating the excellent cyclic capability of single-step co-firing air electrode supported structure. This paper proposes a feasible scheme for developing AS-RePCCs with high performance, stability, and affordable manufacturing.

Probing Local Ion Insertion through Strain-Current Correlation

Among different electrochemical energy storage devices, the ones that store a higher amount of energy (e.g., batteries) often undergo larger ion insertion-induced structural transformation and volume change, which results in lower rate performance. The ones that store a lower amount of energy (e.g., supercapacitors) usually show gradual structural change and smaller volume change. There is a strong correlation between electrochemistry and mechanical properties. Understanding the electro-chemo-mechanical coupling and controlling the ion insertion-induced strain is crucial for achieving high power and high energy storage devices. In-situ atomic force microscopy (AFM) is well suited to tackle this task as it allows tracking local volume changes and other mechanical responses sub-nanometer spatial resolution under the conditions close to the device operationIn this work, we monitored electrode volume change via in-situ AFM and demonstrated the electro-chemo-mechanical coupling behaviors during proton insertion into WO3 materials. The concept of mechanical cyclic voltammetry (mCV) curves was developed, and the relationship between electrochemical current and strain was investigated with simplified models. The results revealed multiple ion-intercalation processes with different mechanical responses are involved during electrode cycling. Local heterogeneity was investigated via mCV mapping, confirming that the charging mechanisms varied across the electrode. These local variations could be further correlated to local morphology, crystal orientations, or chemical compositions. We further demonstrate that the mCV approach is applicable to a variety of energy storage materials (e.g., birnessite and MXene) with the increasing complexity of current-deformation relationships.The work was supported by the Fluid Interface Reactions, Structures, and Transport (FIRST), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Measurements were performed at the Center for Nanophase Materials Sciences (CNMS), which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences.

Constructing O2/O3 homogeneous hybrid stabilizes Li-rich layered cathodes

With the advantages of high energy density and low manufacture cost, lithium-rich layered oxides (LLOs), typically with a layered O3-type structure, are regarded as promising cathodes for lithium-ion batteries (LIBs), but their broad usages are hindered by severe voltage decay over cycling. Although recent progress in O2-type LLOs has aroused interest for their less voltage decay, the critical barrier of unsatisfactory capacity retention has not been overcome yet. To tackle these handicaps, herein we design a new type of LLO (O2/O3-type LLO) with a homogeneous hybrid structure, where the O2 and O3 lattice stacking sequences are arranged alternatively. Benefitting from this novel O2/O3 hybrid structure, the designed material shows greatly improved voltage and capacity stability than that of pure O2- and O3-type LLOs. Revealed by in-situ synchrotron X-ray diffraction and operando differential electrochemical mass spectra, the O2/O3-hybrid LLO cathode shows a more reversible structural evolution, smaller volume change and suppressed oxygen loss during the electrochemical processes. Our approach has initiated a new way to reduce the capacity and voltage decay of LLOs, which endows great promise to the development of high-energy-density LIBs.

Time Course and Clinical Significance of Hematoma Expansion in Moderate-to-Severe Traumatic Brain Injury: An Observational Cohort Study

BackgroundPreventing intracranial hematoma expansion has been advertised as a possible treatment opportunity in traumatic brain injury (TBI). However, the time course of hematoma expansion, and whether the expansion affects outcome, remains poorly understood. In light of this, the aim of this study was to use 3D volume rendering to determine how traumatic intracranial hematomas expand over time and evaluate its impact on outcome.MethodsSingle-center, population-based, observational cohort study of adults with moderate-to-severe TBI. Hematoma expansion was defined as the change in hematoma volume from the baseline computed tomography scan until the lesion had stopped progressing. Volumes were calculated by using semiautomated volumetric segmentation. Functional outcome was measured by using the 12 month Glasgow outcome scale (GOS).ResultsIn total, 643 patients were included. The mean baseline hematoma volume was 4.2 ml, and the subsequent mean hematoma expansion was 3.8 ml. Overall, 33% of hematomas had stopped progressing within 3 h, and 94% of hematomas had stopped progressing within 24 h of injury. Contusions expanded significantly more, and for a longer period of time, than extra-axial hematomas. There was a significant dose–response relationship between hematoma expansion and 12 month GOS, even after adjusting for known outcome predictors, with every 1-ml increase in hematoma volume associated with a 6% increased risk of 1-point GOS deduction.ConclusionsHematoma expansion is a driver of unfavorable outcome in TBI, with small changes in hematoma volume also impacting functional outcome. This study also proposes a wider window of opportunity to prevent lesion progression than what has previously been suggested.

Na3CoZr(PO4)3 as high-voltage cathode material for sodium-ion batteries

Phosphate-based electrode materials are sustainable, abundant, low cost and exhibit stable structures. We report Na3ZrCo(PO4)3 cathode material synthetized through a sol-gel method, that shows high electrochemical performances. The electrochemical activity of Co3+/Co+2 redox couple is reversibly accessed in Na3ZrCo(PO4)3, providing thus high discharge voltage plateaus at 4.05 V. Furthermore, a discharge capacity of 85 mAh g−1 was measured, which is about 80% of the theoretical capacity (106 mAh g−1). These results were obtained with small variations of the lattice parameters and a small volume change of 3.8%, as was confirmed by Operando XRD. These results provide guidelines to improve the electrochemical performance of high-voltage Na3ZrCo(PO4)3 cathode materials for the next generation sodium-ion batteries.

The Influence of Plastic Barriers on Aerosol Infection Risk during Airport Security Checks

Plastic barriers physically separate queuing passengers in airport security check areas as a measure against aerosol transmission. However, this may create “canyons” that interfere with the existing ventilation design: potentially inhibiting airflow, concentrating exhaled viruses, and exacerbating aerosol transmission risk. Accordingly, this study investigated the transmission implications of installing plastic barriers in a security check area with computational fluid dynamics (CFD). Two air distribution schemes were modeled: one with linear air supply diffusers aligned vertically to (Case 1) and another with diffusers parallel with (Case 2) the orientation of partitions. The drift-flux model was used to calculate the spread of viral bioaerosols with 5 µm in diameter; then the Wells–Riley equation was applied to assess aerosol transmission risk for SARS-CoV-2. According to simulation results, in Case 1, installing plastic barriers resulted in relatively small changes in volume with a high infection risk of 1% or greater in the breathing zone within the first 25 min. However, in Case 2, using plastic barriers resulted in the continuous increase in this volume within the first 25 min while this volume was near zero if without plastic barriers. In conclusion, installing plastic barriers needs careful consideration because they do not reduce the risk of airborne SARS-CoV-2 transmission and might even exacerbate it without localized ventilation and air cleaning.

Metallic 3D porous borophosphene: A high rate-capacity and ultra-stable anode material for alkali metal ion batteries

2D borophosphene (B2P2) is a promising next-generation metal ion battery (MIB) anode material, because of the high capacity and low open-circuit-voltage (OCV). Nevertheless, its electrochemical kinetics and cyclability are severely impeded by poor hopping dynamics, small pore size and low mechanical stiffness. In this work, using first principles computations, we design a novel porous 3D boron-based material (named 3D-B2P2) using the corresponding 2D borophosphene nanosheet as a building block. Our computational results show that the resulting 3D-B2P2 has highly dynamical, thermal and mechanical stability. Different from the semi-metallic borophosphene, 3D-B2P2 exhibits intrinsically high metallicity and low mass density (1.20 g/cm3). Its maximum Young's modulus (227.97 GPa) far exceeds that of borophosphere (145.53 GPa), showing a moderate mechanical stiffness. More importantly, due to the uniformly distributed pores and strong affinity towards metal ions, 3D-B2P2 anode achieves high reversible capacities of 691.30, 904.00 and 691.30 mA h/g, suitable OCVs of 1.00, 0.56 and 0.59 V, small volume changes of 2.25%, 6.00% and 8.11%, and low diffusion barriers of 0.25, 0.10 and 0.04 eV for lithium/sodium/potassium ion batteries. All the results indicate that 3D-B2P2 is an appealing anode material for advanced MIBs.

Metallic three-dimensional porous siligraphene as a superior anode material for Li/Na/K-ion batteries

Due to the high specific capacity and low open circuit voltage (OCV), 2D siligraphene has been widely considered as a promising anode material for metal ion batteries (MIBs). Nonetheless, its electrochemical performance is greatly impeded by low mechanical stiffness, poor hopping dynamics and small pore size. Motivated by the great success of 3D carbon materials, we propose a metallic porous 3D-SiC anode using the corresponding 2D tetragonal SiC as a structural unit. By first principles molecular dynamics, mechanical property and phonon spectrum calculations, it is found that 3D-SiC possesses good thermal, mechanical and dynamical stability. The maximum Young’s and bulk moduli of 3D-SiC are 217.16, 400.90 GPa, respectively, exhibiting a moderate mechanical stiffness. More importantly, the intrinsically high electrical conductivity, unique porous structure and low mass density make the 3D-SiC a promising anode candidate for Li/Na/K-ion batteries with small volume changes (6.43 %, 3.75 % and 8.66 %), low diffusion barriers (0.17, 0.19 and 0.017 eV), high storage capacities (947, 947 and 724 mA h/g) and low average OCVs (0.56, 0.34 and 0.11 V). The encouraging results show that siligraphene-based porous 3D anodes are worthy of further investigation for MIBs.

A constant pressure flowmeter for extreme-high vacuum

We demonstrate operation of a constant-pressure flowmeter capable of generating and accurately measuring flows as low as 2 × 10−13 mol s−1. Generation of such small flows is accomplished by using a small conductance element with C ≈ 50 nl s−1. Accurate measurement then requires both low outgassing materials ( mol s−1) and small volume changes ( μl). We outline the present flowmeter’s construction, detail its operation, and quantify its uncertainty. The type-B uncertainty is % (k = 1) over the entire operating range. In particular, we present an analysis of its hydraulic system, and quantify the shift and uncertainty due to the slightly compressible oil. Finally, we compare our flowmeter against a NIST standard flowmeter, and find agreement to within 0.5% (k = 2).

A Stable Three‐Dimensional Porous Carbon as a High‐Performance Anode Material for Lithium, Sodium, and Potassium Ion Batteries

AbstractExtensive efforts are devoted to the design of new carbon materials with improved specific capacity for metal ion batteries (MIBs). One of the effective strategies for such material design is to change the structural unit. Recently, tetracene‐based nanoribbons have been synthesized (Chem. Eur. J. 2019, 25, 12074), which can be used as a basic building block to design a 3D porous TC60 as demonstrated in this work. Based on first‐principles calculations, it is found that the 3D‐TC60 shows high dynamical and thermal stability. Furthermore, the 3D‐TC60 with its unique porosity and various adsorption sites can work as a high‐performance anode material for Li, Na, and K‐ion batteries with high specific capacity of 706, 706, 466 mAhg−1; low diffusion barrier of 0.25, 0.11, 0.08 eV; small volume change of 0.88, 1.96, 2.94%; and average voltage of 0.19, 0.24, 0.50 V, respectively. These intriguing findings suggest the promising prospect of tetracene based materials for battery technology.

Nanoscaled LiMn2O4 for Extended Cycling Stability in the 3 V Plateau.

Extending the potential window toward the 3 V plateau below the typically used range could boost the effective capacity of LiMn2O4 spinel cathodes. This usually leads to an “overdischarge” of the cathode, which can cause severe material damage due to manganese dissolution into the electrolyte and a critical volume expansion (induced by Jahn–Teller distortions). As those factors determine the stability and cycling lifetime for all-solid-state batteries, the operational window of LiMn2O4 is usually limited to 3.5–4.5 V versus Li/Li+ in common battery cells. However, it has been reported that nano-shaped particles and thin films can potentially mitigate these detrimental effects. We demonstrate here that porous LiMn2O4 thin-film cathodes with a certain level of off-stoichiometry show improved cycling stability for the extended cycling range of 2.0–4.5 V versus Li/Li+. We argue through operando spectroscopic ellipsometry that the origin of this stability lies in the surprisingly small volume change in the layer during lithiation.

Deep-fUS: A Deep Learning Platform for Functional Ultrasound Imaging of the Brain Using Sparse Data

Functional ultrasound (fUS) is a rapidly emerging modality that enables whole-brain imaging of neural activity in awake and mobile rodents. To achieve sufficient blood flow sensitivity in the brain microvasculature, fUS relies on long ultrasound data acquisitionsat high frame rates, posing high demands on the sampling and processing hardware. Here we develop an image reconstruction method based on deep learning that significantly reduces the amount of data necessary while retaining imaging performance. We trained convolutionalneural networks to learn the power Doppler reconstruction function from sparse sequences of ultrasound data with compression factors of up to 95%. High-quality images from in vivo acquisitions in rats were used for training and performance evaluation. We demonstrate that time series of power Doppler images can be reconstructed with sufficient accuracy to detect the small changes in cerebral blood volume (~10%) characteristic of task-evoked cortical activation, even though the network was not formally trained to reconstruct such image series. The proposed platform may facilitate the development of this neuroimaging modality in any setting where dedicated hardware is not available or in clinical scanners.

Lung ultrasound of the dependent lung detects real-time changes in lung volume in the preterm lamb

BackgroundEffective lung protective ventilation requires reliable, real-time estimation of lung volume at the bedside. Neonatal clinicians lack a readily available imaging tool for this purpose.ObjectiveTo determine the ability of lung...