Effect Of Volume Change Research Articles

Decreased volume of rectus femoris and iliocapsularis in patients with femoroacetabular impingement syndrome after primary hip arthroscopy

Purpose(1) to investigate the consecutive changes in hip muscle volume in patients with femoroacetabular impingement syndrome (FAIS) during the initial postoperative period, and (2) to determine the potential effect of the early changes in hip muscle volume on clinical outcomes.MethodsData between March 2021 and March 2022 was reviewed. Patients diagnosed with FAIS based on clinical symptoms and radiographic findings, and undergoing hip arthroscopic treatment were included. Exclusion criteria were incomplete MRI data, prior history of hip surgery, and concomitant hip conditions including hip osteoarthritis with a Tönnis grade > 1, avascular necrosis, Legg-Calvé-Perthes disease, osteoid osteoma, synovial chondromatosis, pigmented villonodular synovitis, and developmental dysplasia of the hip (DDH). MRI was performed preoperatively and 3, 6, 12-month postoperatively. Cross-sectional area (CSA) of hip muscles including rectus femoris (RF), iliocapsularis (IC), iliopsoas (IP), gluteus medius/minimus complex (G-med/min), and gluteus maximus (G-max) were collected on MRI. The CSA was corrected by body surface area (BSA). Preoperative and a minimum of 2-year postoperative patient-reported outcome (PRO) scores including Visual Analog pain Scale (VAS), modified Harris Hip Score (mHHS), and international Hip Outcome Tool, 12-component form (iHOT-12) were collected. A multivariate linear regression model was built to determine the influence of the potential factors on postoperative PROs.ResultsA total of 76 patients were included in the study. Compared to the preoperative level, decreased volume of RF and G-max, and increased IC/RF ratio were observed at postoperative 3 months (all with P < .05). Both G-med/min and G-max presented decreased volume at postoperative 6 months (all with P < .05). G-med/min presented decreased volume (P = .001) at postoperative 12 months. Changes in RF at postoperative 3 months and 12 months were positively related to improvement of iHOT-12 (Beta = 0.371, P = .012 and Beta = 0.330, P = .026, respectively). Changes in IC at postoperative 6-month was positively related to improvement of mHHS (Beta = 0.367, P = .027) and iHOT-12 (Beta = 0.315, P = .044).ConclusionDuring the initial first year following arthroscopic treatment for FAIS, decreased volume of the RF and gluteal muscles was observed. Early changes in volume of RF and IC were positively correlated to the improvement of minimum 2-year PROs.Level of evidenceLevel IV; case series.

Vibroscope method for determination of cross-sectional area of glass and carbon fibres – Theory and further development

Accurate determination of cross-sectional area of glass and carbon fibres by the vibroscope method is examined. Complete derivations of the central frequency solutions are presented, to make these derivations accessible in modern scientific literature. The effect of non-zero bending stiffness is included. The influence of shape of fibre cross-sectional area is analysed. Only small deviations in cross-sectional areas are found due to fibre shape, allowing for the use of the vibroscope method for fibres with non-circular cross-sectional areas. Two correction factors are introduced for the effect of volume change and area change of a tensioned fibre, allowing determination of the cross-sectional area of the non-tensioned fibre. A model plot of the vibroscope equation is presented, showing the numerical effect of the corrections on the fibre cross-sectional area depending on the applied tension force. The relations shown by the model plot have implications for the experimental settings of the vibroscope method.

Biomechanical effects of deltoid muscle atrophy on rotator cuff tissue: a finite element study

The deltoid muscle and rotator cuff tissue are structural components that maintain the dynamic stability of the shoulder joint. However, atrophy of the deltoid muscle may affect the stability of the shoulder joint, which in turn alters the mechanical distribution of rotator cuff tissue. Currently, the effect of muscle volume changes in the deltoid muscle on reducing the load on the rotator cuff tissue is still unknown. Therefore, this paper intends to analyze the mechanical changes of rotator cuff tissue by deltoid muscle atrophy through finite elements. Based on previously published finite element shoulder models, the deltoid muscle was modeled by constructing deltoid muscle models with different degrees of atrophy as, 100% deltoid muscle (Group 1), 80% deltoid muscle (Group 2), and 50% deltoid muscle (Group 3), respectively. The three models were given the same external load to simulate glenohumeral joint abduction, and the stress changes in the rotator cuff tissue were analyzed and recorded. In all three models, the stress in the rotator cuff tissue showed different degrees of increase with the increase of abduction angle, especially in the supraspinatus muscle. At 90° of glenohumeral abduction, supraspinatus stress increased by 58% and 118% in Group 2 and Group 3, respectively, compared with Group 1; In the subscapularis, the stress in Group 3 increased by 59% and 25% compared with Group 1 and Group 2, respectively. In addition, the stress of the infraspinatus muscle and teres minor muscle in Group 2 and Group 3 were higher than that in Group 1 during the abduction angle from 30° to 90°. Deltoid atrophy alters the abduction movement pattern of the glenohumeral joint. During glenohumeral abduction activity, deltoid atrophy significantly increases the stress on the rotator cuff tissue, whereas normal deltoid volume helps maintain the mechanical balance of the rotator cuff tissue.

Investigating Plastic Deformation Between Silicon and Solid Electrolyte in All-Solid-State Batteries Using Operando X-ray Tomography

Si anodes in all-solid-state batteries are expected to achieve high energy density and durability because large volume changes in Si can be mechanically suppressed by the hardness of solid electrolytes. However, the effects of volume changes on the mechanical interface between Si and solid electrolytes during charge/discharge reactions have not been investigated. In this study, operando X-ray computed tomography was used to determine the microstructure of an all-solid-state battery comprising Si active materials and a solid sulfide electrolyte, Li10GeP2S12, during charge/discharge reactions. To evaluate the volume expansion/contraction effects on the charge/discharge properties, the tortuosity of the ion conduction path and the contact area fraction between Si and the solid electrolyte during the charge/discharge reactions were quantitatively estimated. Shell-shaped voids around the Si particles were observed after Si shrinkage owing to the plastic deformation of the solid electrolyte. This characteristic resulted in poor charge/discharge efficiency and incomplete delithiation in the battery. These results will facilitate the design optimization of Si composite electrodes, which will be highly beneficial to the development of effective all-solid-state batteries.

Photogrammetry-Based Method for Measuring Volume Changes of Soil Specimens During Critical Phases of Triaxial Testing

Triaxial tests has been routinely used to measure the stress–strain relationship for geomaterials. During triaxial testing, many sources of errors that cannot be completely avoided but are often ignored or approximated using empirical equations. This paper presents a systematic investigation of soil volume change, volume strain nonuniformity, and cross-sectional calculation along the specimen during triaxial testing using a photogrammetry-based method. Consolidated drained triaxial tests were performed in which two parallel measurements were taken: (1) relative volume using the conventional triaxial testing and (2) absolute volume using the photogrammetry-based method. The difference in the observed volume and void ratio measurements between the two methods highlighted the importance of absolute soil volume over the relative volume method. The results revealed the effect of soil volume change in the interpretation of triaxial testing findings. Various preparation steps and procedures during triaxial testing have influenced the initial measured volume and thus caused deviation of the subsequent associated measurements. This method would present a quality control approach for different aspects of triaxial testing to improve the test simulations to accurately measure the soil behavior. The proposed method is important for more refined simulations and identification of setup-induced errors. Additional applications of the current research would allow correct determination of the stress path followed during triaxial testing, the critical-state soil mechanics parameters, and the stress–strain relationship, including deformation and strength parameters.

Relaxação não-linear de tensões do poli(metacrilato de metilo)

Nonlinear stress relaxation is much more difficult to model than creep. This model, although still simplified, describes a clearly non-linear (strain-dependent) behavior that only becomes linear for very low strains; is the first to explain the effect of small differences between the level of the initial and final moduli, as is the case in semi-crystalline materials; explicitly quantifies the effect of temperature, when considering the distribution of relaxation times; can be extended to also take into account the effect of changes in free volume; and ensure a very fast calculation of relevant physical parameters and extrapolate long-term behavior at any temperature, from experiments close to room temperature, lasting just a few hours. The model can, however, still be updated and, eventually, also take into account the effect of the rapid initial deformation ramp up to its nominal value. The work also analyzes in detail the meaning of the values and physical characteristics of the model parameters, applied to poly(methyl methacrylate) – PMMA, with temperatures of 30, 40 and 50 ºC, and deformations of 3, 4 and 5%.

Applying isovolumic steam capsule as new thermal energy storage unit

In order to make up the inefficiencies of liquid–solid phase change material (PCM) such as low latent heat and low heat transfer rate, the possibility of adopting water steam as the phase change material is explored. Although great volume change occurs during the gas–liquid phase-changing, the specific latent heat is at least one order of magnitude larger than that of liquid–solid phase-changing. To minimize the adverse effect of the great volume change during vaporization or condensation, the steam can be accommodated inside sealed vessel with sturdy shell. In this study, an isovolumic steam capsule (ISC) was made by filling a cylinder with a small amount of liquid water and then heated and boiled to extinguish the non-condensable gas (NCG) before sealing it. Thermodynamic analysis shows the thermal energy contained in the isovolumic steam capsule per unit volume increases in approximately an exponential manner with the increase of temperature due to the evaporation of liquid, and can reach several times that of liquid–solid phase change material, demonstrating great potential as energy storage material. The heat transfer experiments show that the energy charging and discharging rates increase with the temperature difference. There exists thermodynamic non-equilibrium during heat transfer and the deviation from saturation enlarges with increasing temperature difference and non-condensable gas concentration. For both charging (vaporization) and discharging (condensation), a higher non-condensable gas concentration in the steam exhibits larger heat transfer rate in the beginning, but smaller heat transfer rate in the later stage. The mechanism of vaporization and condensation in the isovolumic steam capsule awaits to be further clarified.

Development of Supercapacitors with 3D Porous Structures

AbstractInvited for this issue's Front Cover is the group from K. H. (Koko) Lam (The Hong Kong Polytechnic University, University of Glasgow). The front cover picture illustrates 3D interconnected nanoporous electrodes featuring a nano‐cage structure, wrapping active materials within. This distinctive electrode design enhances contact between active materials, electrolytes, and current collectors. It also alleviates the adverse effect of volume change in active materials and elevates the mass loading of nanostructured active materials within the electrodes. Consequently, this nanostructure significantly enhances the overall electrochemical properties of the electrodes. Read the full text of the Concept at 10.1002/celc.202300618.

Visceral Adipose Tissue Reduction Measured by Deep Neural Network Architecture Improved Reflux Esophagitis Endoscopic Grade.

Visceral obesity is a risk factor for reflux esophagitis (RE). We investigated the risk of RE according to visceral adipose tissue (VAT) measured by deep neural network architecture using computed tomography (CT) and evaluated the longitudinal association between abdominal adipose tissue changes and the disease course of RE. Individuals receiving health checkups who underwent esophagogastroduodenoscopy (EGD) and abdominal CT at Seoul National University Healthcare System Gangnam Center between 2015 and 2016 were included. Visceral and subcutaneous adipose tissue areas and volumes were measured using a deep neural network architecture and CT. The association between the abdominal adipose tissue area and volume and the risk of RE was evaluated. Participants who underwent follow-up EGD and abdominal CT were selected; the effects of changes in abdominal adipose tissue area and volume on RE endoscopic grade were investigated using Cox proportional hazards regression. We enrolled 6,570 patients who underwent EGD and abdominal CT on the same day. RE was associated with male sex, hypertension, diabetes, excessive alcohol intake, current smoking status, and levels of physical activity. The VAT area and volume increased the risk of RE dose-dependently. A decreasing VAT volume was significantly associated with improvement in RE endoscopic grade (hazard ratio: 3.22, 95% confidence interval: 1.82-5.71). Changes in subcutaneous adipose tissue volume and the disease course of RE were not significantly correlated. Visceral obesity is strongly associated with RE. VAT volume reduction was prospectively associated with improvement in RE endoscopic grade dose-dependently. Visceral obesity is a potential target for RE treatment.

Confluence of ZnO and PTFE Binder for Enhancing Performance of Thin‐Film Lithium‐Ion Batteries

Developing anode materials with high specific capacity and cycling stability is vital for improving thin‐film lithium‐ion batteries. Thin‐film zinc oxide (ZnO) holds promise due to its high specific capacity, but it suffers from volume changes and structural stress during cycling, leading to poor battery performance. In this research, we ingeniously combined polytetrafluoroethylene (PTFE) with ZnO using a radio frequency (RF) magnetron co‐sputtering method, ensuring a strong bond in the thin‐film composite electrode. PTFE effectively reduced stress on the active material and mitigated volume change effects during Li+ ion intercalation and deintercalation. The composite thin films are thoroughly characterized using advanced techniques such as X‐ray diffraction, scanning electron microscopy, and X‐ray photoelectron spectroscopy for investigating correlations between material properties and electrochemical behaviors. Notably, the ZnO/PTFE thin‐film electrode demonstrated an impressive specific capacity of 1305 mAh g−1 (=7116 mAh cm−3) at a 0.5C rate and a remarkable capacity retention of 82% from the 1st to the 100th cycle, surpassing the bare ZnO thin film (50%). This study provides valuable insights into using binders to stabilize active materials in thin‐film batteries, enhancing battery performance.

Exploring the effect of volume change on capillary soil water retention in an undisturbed silty clay: an experimental and modeling approach

Exploring the effect of volume change on capillary soil water retention in an undisturbed silty clay: an experimental and modeling approach

Numerical Analysis of Effect of Plastic Change in Volume and Stress Mode in Boundary Value Problems of Plasticity

Numerical Analysis of Effect of Plastic Change in Volume and Stress Mode in Boundary Value Problems of Plasticity

(Invited) SiO and LiNi0.5Mn1.5O4 Composite Electrodes with Functional Polymer Binders

This study focuses on the optimization of polymer binders in lithium-ion batteries (LIBs) to facilitate the development of high-energy-density storage devices. Despite 30 years of commercialization, the demand for high energy density storage devices has continued to increase, making LIBs a topic of significant research interest. One major avenue of research has focused on high-voltage positive electrode materials such as LiNi0.5Mn1.5O4 (LNMO) and high-capacity negative electrode materials like SiO. However, the practical use of these materials is hindered by issues associated with electrolyte decomposition and large volume changes during the charge-discharge process.To address these challenges, we explored the chemistry of polymer binders blended in composite electrodes to maintain the structure of the electrode and form a passivation/protective layer on the active material surface to suppress side reactions.(1, 2) In particular, we investigated the use of "functional binders" to improve the performance of high-voltage LNMO composite electrodes. We synthesized sulfated alginate binders, which are significantly cheaper and stiffer than commonly used poly(vinylidene fluoride) (PVdF) and uniformly cover the surface of LNMO.(3)The high polarity of the sulfate group also increased the binder's affinity for the electrolyte. During the initial charge-discharge cycle, the electrolyte decomposition products generated on the alginate-covered active materials participated in the formation of a protective passivation layer that suppressed further decomposition during subsequent cycles, resulting in enhanced cycling and rate performances.We also explored the use of partially-neutralized crosslinked sodium polyacrylate (CLPA) binders with flexible monomers to mitigate the effects of volume changes in SiO electrodes.(4)Additionally, we investigated the “maturation” effects on battery performances by storing the composite electrodes with CLPA-based binders in a humid atmosphere for a few days before drying. Our results show that the binder with 20% flexible monomer (CLPA-20) exhibited the highest peel strength and long-term cyclability, and the maturation treatment further improved these properties. Cross-sectional SEM images revealed that the binder and conductive carbon were uniformly dispersed in the composite layer in the matured electrodes, indicating the migration of active materials and binders during the maturation process. Furthermore, surface analysis of the cycled electrode showed that the superior mechanical properties of the electrode endowed by the maturation treatment helped in maintaining the passivation layer on the active material surface, resulting in improved cycling performance.Overall, our findings suggest that optimizing polymer binders can enhance the performance of LIBs by controlling the electrode reaction via binder chemistry. The strategies developed in this study could facilitate the future development of high-energy-density LIBs, making them more accessible and commercially viable for various applications.References (1) R. Tatara, S. Komaba et al., ChemElectroChem, 8, 4345 (2021).(2) H. Isozumi, R. Tatara, S. Komaba et al., ACS Appl. Energy Mater., 3, 7978 (2020).(3) A. Oishi, R. Tatara, S. Komaba et al., ACS Appl. Mater. Interfaces, 14, 51808 (2022).(4) S. Yamazaki, R. Tatara, S. Komaba et al., Mater. Adv., 4, 1637 (2023).

Carbon quantum dot-assisted VO2(D) welding on holey graphene for zinc-ion battery cathode materials

Superior-quality zinc-ion batteries utilizing nanopseudocapacitor materials and flexible, three-dimensional, highly conductive porous carbon materials are current research hotspots. But the inadequate dispersion between the system components and the dissolution of the pseudocapacitive materials severely limit the further application of VO2-watery zinc-ion battery components (ZIBs). In this work, we create a novel type of independent VO2(D) covered with carbon quantum dots and assist in its welding on holey graphene (CVH). Composite structures of graphene-supported VO2(D) were designed by a simple solvothermal reaction and ultrasonic self-assembly. The CQD coating acts as a conductive medium, facilitating charge transfer to the surface and also mechanically stabilizing the cathode during volume changes, while the CQD acts as a “bridge” to form an intimate interfacial relationship with the HG. The introduction of HG not only provides more sites of activity and longitudinal transport pathways for electron and ion diffusion, but also makes the overall structure more stable and effective in eliminating the effect of volume change and realizing large pseudocapacitance. The electrochemical results show that CVH has an ultra-strong specific capacity of 443 mA h g−1 at 0.1 A/g, and a capacity retention of 332 mAh g−1 after 1000 cycles at 0.5 A/g. Excellent electrochemical performance for Zn2+ ion storage is found in CVH. This unusual structure may help us understand developing ZIB cathodes better while also offering fresh perspectives on high-performance batteries.

Modeling and Analysis of Coupled Thermal and Mechanical Capacity Degradation in Silicon-Based Lithium-Ion Batteries

Large-format cells are gaining popularity for battery electric vehicles (BEVs) to maximize volumetric and gravimetric energy densities but are associated with challenges in ensuring adequate thermal management. Spatial current density and temperature variations negatively affect overall cell utilization and lifetime.In addition, the mechanical stresses generated within the silicon-based battery electrodes also cause aging and resultant capacity loss. The coupled effects of the thermal and mechanical factors could thus particularly exacerbate cell capacity degradation. Rigorous mechano-thermo-electrochemical models for battery degradation can be a powerful complementary tool to understand these phenomena better. Simulating performance scenarios can significantly improve cell design and experimentation while reducing time and cost commitments. Model-based design approaches thus have the potential to yield substantial economic benefits.This work shall serve as an extension to the previously developed thermal degradation model for non-uniform aging in lithium-ion batteries by coupling with mechanical models predicting the effects of volume change within the batteries over cycling. The observed capacity fade trend for a given battery is ultimately the result of an interplay between multiple degradation mechanisms, which depend on a range of design and operating parameters. The errors between the model predictions and experimental data can provide information on the suitability of a given model and the relative prevalence of a given degradation mechanism, with functional and practical benefits, as there exists significant variation in the parameters, mechanisms, and predictive capability of models in the literature. In addition, a rigorous model of volume changes increases the accuracy of predictions of dynamic stress-strain profiles, which in turn helps improve predictions of associated mechanical degradation phenomena. As a first step towards including mechanical effects, the current model builds on the previously reported studies for modeling volume change in porous electrodes due to intercalation (deintercalation) during lithiation (delithiation). This volume change leads to dimensional and porosity changes in the porous electrodes. Furthermore, these mechanical models will help predict generated stresses and strain profiles within the battery and will be related to models of resultant degradation, especially in the case of silicon/graphite electrodes characterized by substantial volume changes.

Power profile analysis of criticality accidents involving fissile solution boiling with considering evaporation

ABSTRACT The total fission energy released in a criticality accident involving fissile solution boiling tends to be high because the relatively high fission power continues during boiling. Simulating fission power change correctly during boiling seems essential to estimate the total fission energy. Fission power during boiling changes depending on fissile concentration and volume as the solution evaporates. In this study, we investigated the effect of concentration and volume change on estimated total fission energy for a long time of boiling. We introduced a model calculating the evaporation of fissile solution into the modified quasi-steady-state method to simulate power change during boiling. Three CRAC experiments and the Idaho Chemical Processing Plant (ICPP) criticality accident in 1959 were analyzed. As a result, the calculated energy considering concentration and volume change during boiling reproduced the measured energy well.

Competing effects of wetting and volume change on G0 in compacted loess

This paper explores the relative contributions of wetting (suction reduction) and its associated volume change on the small-strain shear stiffness, G0, in compacted loess from Xi’an, China. Results from one-dimensional compression tests with measurements of the shear wave velocity upon wetting and loading paths are presented. The experimental results show that the softening caused by wetting compete with the densification caused by plastic deformation and their effects on G0 are strongly controlled by stress level applied prior to wetting. Below the compaction stress, suction effects are dominant and G0 reduces irrespective of the magnitude of the collapse strain. With the increase in the stress level, the reduction in G0 caused by saturation is compensated by the plastic deformation triggered by soil collapse. This behaviour is clearly observed when the soil is first loaded to the compaction stress, where the maximum collapse strain is measured upon wetting. Volume change is dominant once the compaction stress is exceeded so that G0 tends to increase upon wetting. A wetting-induced stiffness factor D is defined to demonstrate that the change in G0 varies linearly with the stress level and this behaviour is independent of the compaction conditions.

Parametric Study on the Behavior of Deep Cylindrical Excavationsin Saturated Clay

ABSTRACT This study investigates the coupled soil deformation and pore fluid flow in saturated clay around a cylindrical excavation, utilizing finite element analysis and Modified Cam-Clay constitutive law. Validation of the numerical model precedes a parametric study, assessing volume change effects and various parameters on wall and ground deformations, stresses, pore water pressures, and hydraulic gradients. Results underscore the significance of soil parameters, particularly the Kappa value (κ) influencing horizontal displacements and hydraulic properties impacting settlements and basement heave. Retaining wall length minimally affects stresses but crucially influences water flow from the excavation base. Wall thickness significantly reduces horizontal displacements, with added ground settlement benefits, while constructing a bottom deck substantially mitigates settlements and displacements. This thorough analysis advances understanding of soil-structure interactions, offering vital insights for engineering practices concerning cylindrical excavations in soft soil conditions.

Bladder-Induced Compression of the External Iliac Veins: Recognition and Implications for Treatment.

The effect of changes in bladder volume on the caliber of adjacent veins is underappreciated but essential to recognize to avoid complications such as unnecessary stenting or clot migration causing pulmonary embolism. Here the authors illustrate the importance of this finding in 3 cases using venographic and endovascular sonographic imaging: the first in which BPH-induced chronic bladder outlet obstruction resulted in DVT formation, the second in which the cause was unrecognized and unnecessary stenting performed, and the third in which inappropriate treatment was avoided by decompressing the bladder.

Modeling Diffusion-Induced Mechanical Degradation in Dual-Graphite Battery Cathodes: Application to Intercalation

In this work, we propose a finite element framework to analyze the diffusion-induced mechanical degradation in graphite active particles (APs) due to bulky anion intercalation in dual-graphite batteries (DGBs). Finite strain formulation is considered to account for the large volume expansion that typically occurs in graphite cathodes. The proposed model considers chemo-mechanical coupling, including the effect of the particle volume changes due to the penetration of ions and its eventual fracture, modeled using a phase-field fracture approach. To account for the stochastic nature of graphitic microstructures, the mechanical properties are described by means of a Weibull distribution function. Our model is able to reproduce realistic cracking patterns that take place during the charging and discharging processes in APs. Finally, we use the model to simulate different galvanostatic charging rates and particle sizes to provide insight into the mechanical degradation of graphite APs during intercalation. We use this information to provide design rules for improved graphite cathodes or better operation strategies in DGBs.