Effective Volume Research Articles

Development and assessment of an actuator volume method in rotating frame for predicting the flow-field of horizontal-axis wind turbines

The prediction of the unsteady flow-field in horizontal-axis wind turbines using blade-resolved CFD simulations is challenging and computationally demanding. The simulations become more affordable when using a representation of the blades based on the generalized actuator disc concept; however, the projection of the computed forces in the computational domain introduces additional mesh parameters and requires codes that impact the computation time in unstructured solvers and parallel computing. In this work, a new approach to model the effects of the rotating blades using source terms and a sliding mesh technique is proposed. The developed framework also includes the tower and nacelle. The force distributions are obtained using an in-house code, which incorporates Buhl’s correction, three-dimensional effects, and tip and hub loss corrections. The validation was performed against blade-resolved simulations and experimental data at three tip-speed ratios. At design conditions, both models are in good agreement in terms of velocity deficit and angle of attack, being underestimated at off-design conditions. The local effects of the actuator volumes, the induction region, and the near-wake have been analysed in detail. This new approach is flexible, robust, and provides good accuracy, whereas the computational cost is considerably lower than high-fidelity simulations.

Effect of Abaca Bracts Biocarbon Volume and Infill Ratio on Mechanical, Wear, Fatigue and Hydrophobic Behaviour of Acrylonitrile Butadiene Styrene Biocomposites Tailored Using 3D Printing

Effect of Abaca Bracts Biocarbon Volume and Infill Ratio on Mechanical, Wear, Fatigue and Hydrophobic Behaviour of Acrylonitrile Butadiene Styrene Biocomposites Tailored Using 3D Printing

Effect of free volume on nonlinear optical characteristics of P(St-co-MMA)/CuO and PSAN/CuO polymer nanocomposites

Microstructural dependance of nonlinear optical (NLO) properties of Poly (Styrene-co-Methylmethacrylate) (P(St-co-MMA)/Cupric Oxide (CuO) and Poly(styrene-co-Acrylonitrile) (PSAN)/CuO polymer nanocomposites (PNCs) has been explored. The positron lifetime parameter viz., free volume hole size (Vf) and NLO parameters viz., third-order nonlinear absorption coefficient (β) and nonlinear refractive index (n2)) are maximum at 0.4 wt% and 1.0 wt% of CuO nanoparticles loadings in P(St-co-MMA)/CuO and PSAN/CuO PNCs respectively. The crystallinity and optical energy band gap decreased in P(St-co-MMA)/CuO and PSAN/CuO PNCs at 0.4 wt% and 1.0 wt% of CuO nanoparticles loading respectively. The reduced optical energy band gap and the formation of bigger free volumes promote the dipole polarization and therefore the NLO properties of P(St-co-MMA)/CuO and PSAN/CuO PNCs.

A novel approach to determine spatial prioritization of flooding mitigation practices based on coupled hydrodynamic and rainfall-tracking model

Abstract This article is focused on proposing a novel approach to determining flood mitigation practices based on coupled hydrodynamic and rainfall-tracking models. V-shaped and Baogaisi catchments were applied to assess the effects of the novel approach in mitigating peak discharge and runoff volume, respectively. Specifically, traditional afforestation scenarios were planned from downstream to upstream, while novel afforestation scenarios were designed based on the maximum and minimum contribution rate of sub-areas. Then two types of cases were simulated by the coupled hydrodynamic and rainfall-tracking model again to evaluate the mitigating effects of different afforestation practices. Results show that the coupled model is able to obtain accurate hydrodynamic and rainfall-tracing information simultaneously within each computing grid under the flooding caused by rainfall events. Moreover, in comparison with the reduction effects of traditional cases, results simulated under two catchments illustrated that the novel approach is able to determine spatial prioritization of afforestation management practices. In particular, there is a positive correlation between the contribution rate of afforestation area and the reduction effect of runoff volume caused by rainfall events. Thus, the research could provide a more scientific and reasonable guide in determining spatial prioritization flooding mitigation practices for planners and governments.

Experimental study on the freezing process of water droplets for ice air jet technology

Ice air jet technology is one non-destructive, residue-free and environmentally friendly machining process. It is an efficient method to form ice particles by atomizing water droplets in ultra-low temperature environment. The freezing characteristics of water droplets in cryogenic gas and liquid nitrogen environment are visually analyzed, and the effects of droplet volume, ambient temperature are also studied. The results show that when water droplets freeze in a cryogenic gas environment, four distinct stages are observed, namely pre-cooling stage, recalescence stage, solidification stage, and deep cooling stage. However, when water droplets freeze in liquid nitrogen, the recalescence stage cannot be observed. For a 5 µl water droplet, it takes 68 s for water droplets to freeze into ice particles at − 20.36 °C, while it takes only 1.7 s in liquid nitrogen. During the freezing process, the water droplets form an ice shell outside and freeze inwardly. Ice particles may break up due to differences in solubility and density. With the increase of volume the time spent on pre-cooling stage and freezing stage both increases. For the large latent heat of water phase transformation, the solidification stage time is greatly affected by the volume of water droplets. When the ambient temperature drops from − 10.67 °C to − 24.68 °C, the freezing time of 5 µl water droplets decreases by 45.5%, indicating that the ambient temperature has a great influence on the freezing time. The results of the study can significantly contribute to the development of ice air jet technology.

From 0D to 3D: Hierarchical structured high-performance free-standing silicon anodes based on binder-induced topological network architecture

Free-standing silicon anodes with high proportion of active materials have aroused great attention; however, the mechanical stability and electrochemical performance are severely suppressed. Herein, to resolve the appeal issues, a free-standing anode with a “corrugated paper” shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed. Essentially, an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions. In which, the hierarchical interlocking structure is achieved by directional induction of the binder, which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes. Benefiting from it, this anode exhibits outstanding performance under harsh service conditions including high Si loading, ultrahigh areal capacity (33.2 mA h cm−2), and high/low temperatures (−15–60 °C), which significantly extends its practical prospect. Furthermore, the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process. Thus, from both the fundamental and engineering views, this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.

Multi-instance learning based lung nodule system for assessment of CT quality after small-field-of-view reconstruction

Small-field-of-view reconstruction CT images (sFOV-CT) increase the pixel density across airway structures and reduce partial volume effects. Multi-instance learning (MIL) is proposed as a weakly supervised machine learning method, which can automatically assess the image quality. The aim of this study was to evaluate the disparities between conventional CT (c-CT) and sFOV-CT images using a lung nodule system based on MIL and assessments from radiologists. 112 patients who underwent chest CT were retrospectively enrolled in this study between July 2021 to March 2022. After undergoing c-CT examinations, sFOV-CT images with small-field-of-view were reconstructed. Two radiologists analyzed all c-CT and sFOV-CT images, including features such as location, nodule type, size, CT values, and shape signs. Then, an MIL-based lung nodule system objectively analyzed the c-CT (c-MIL) and sFOV-CT (sFOV-MIL) to explore their differences. The signal-to-noise ratio of lungs (SNR-lung) and contrast-to-noise ratio of nodules (CNR-nodule) were calculated to evaluate the quality of CT images from another perspective. The subjective evaluation by radiologists showed that feature of minimal CT value (p = 0.019) had statistical significance between c-CT and sFOV-CT. However, most features (all with p < 0.05), except for nodule type, location, volume, mean CT value, and vacuole sign (p = 0.056–1.000), had statistical differences between c-MIL and sFOV-MIL by MIL system. The SNR-lung between c-CT and sFOV-CT had no statistical significance, while the CNR-nodule showed statistical difference (p = 0.007), and the CNR of sFOV-CT was higher than that of c-CT. In detecting the difference between c-CT and sFOV-CT, features extracted by the MIL system had more statistical differences than those evaluated by radiologists. The image quality of those two CT images was different, and the CNR-nodule of sFOV-CT was higher than that of c-CT.

Dysphagia Pattern in Early to Moderate Parkinson's Disease Caused by Abnormal Pharyngeal Kinematic Function.

Airway invasion is common in patients with Parkinson's disease (PD) and can cause serious complications. However, a PD-related dysphagic pattern has not been clearly elucidated. In this study, 53 patients with early to moderate PD were enrolled to undergo a videofluoroscopic study of swallowing evaluation (VFSS) and a battery of neuropsychological assessments. A set of VFSS variables (three visuoperceptual, nine temporal, and six spatial) were measured. The main effects of bolus viscosity and volume on airway invasion were calculated. Statistical analyses were performed to determine key kinematic factors of airway invasion for swallowing each bolus type. Airway invasion frequency was significantly higher for liquid boluses (liquid vs. pudding P < 0.001; liquid vs. honey P = 0.006). Laryngeal vestibule closure reaction time (LVCrt) was the key kinematic factor of airway invasion for 3ml liquid swallow (P = 0.040), anterior displacement of hyoid bone was the key kinematic factor for both 5ml and 10ml liquid swallows (P = 0.010, 0.034, respectively). Male sex and advanced Hoehn and Yahr stage were significantly related to reduced anterior displacement of hyoid bone. These results reveal the dysphagic pattern related to PD, demonstrating that prolonged LVCrt and reduced anterior displacement of hyoid bone are two crucial kinematic factors contributing to airway invasion during the liquid swallow. In addition, hyoid bone dysfunction was correlated with disease severity and male sex. Our findings warrant further investigation of the pathophysiological mechanism of dysphagia in PD and would guide clinical intervention.

Anatomy-based correction of kidney PVE on 177Lu\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{177}\ ext{Lu}$$\\end{document} SPECT images

BackgroundIn peptide receptor radionuclide therapy (PRRT), accurate quantification of kidney activity on post-treatment SPECT images paves the way for patient-specific treatment. Due to the limited spatial resolution of SPECT images, the partial volume effect (PVE) is a significant source of quantitative bias. In this study, we aimed to evaluate the performance and robustness of anatomy-based partial volume correction (PVC) algorithms to recover the accurate activity concentration of realistic kidney geometries on 177\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{177}$$\\end{document}Lu SPECT images recorded under clinical conditions.MethodsBased on the CT scan data from patients, three sets of fillable kidneys with surface-to-volume (S:V) ratios ranging from 1.5 to 2.8 cm−1, were 3D printed and attached in a IEC phantom. Quantitative 177\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{177}$$\\end{document}Lu SPECT/CT acquisitions were performed on a GE Discovery NM CT 870 DR camera for the three modified IEC phantoms and for 6 different Target-To-Background ratios (TBRs: 2, 4, 6, 8, 10, 12). Two region-based (GTM and Labbé) and five voxel-based (GTM + MTC, Labbé + MTC, GTM + RBV, Labbé + RBV and IY) methods were evaluated with this data set. Additionally, the robustness of PVC methods to Point Spread Function (PSF) discrepancies, registration mismatches and background heterogeneity was evaluated.ResultsWithout PVC, the average kidney RCs across all TBRs ranged from 0.66 ± 0.05 (smallest kidney) to 0.80 ± 0.03 (largest kidney). For a TBR of 12, all anatomy-based method were able to recover the kidneys activity concentration with an error < 6%. All methods result in a comparable decline in RC restoration with decreasing TBR. The Labbé method was the most robust against PSF and registration mismatches but was also the most sensitive to background heterogeneity. Among the voxel-based methods, MTC images were less uniform than RBV and IY images at the outer edge of high uptake areas (kidneys and spheres).ConclusionAnatomy-based PVE correction allows for accurate SPECT quantification of the 177\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{177}$$\\end{document}Lu activity concentration with realistic kidney geometries. Combined with recent progress in deep-learning algorithms for automatic anatomic segmentation of whole-body CT, these methods could be of particular interest for a fully automated OAR dosimetry pipeline with PVE correction.

Impact of Electrode Distance in a Quasi-Uniform Model Electrode System on Lightning Impulse Breakdown Voltage in Various Insulating Liquids

This study presents findings on the influence of gap length distance on the lightning impulse breakdown voltage of three dielectric liquids of different chemical origins. The liquids were tested in a model electrode system with a quasi-uniform electric field distribution and a pressboard plate placed on the grounded electrode. The experimental studies were supported using calculations and simulations to show the individual relationships between the lightning impulse breakdown voltage and gap distance, which represent the so-called volume effect of the most stressed liquid. The results of the experiment, which involved four considered gap distances of 2, 4, 6, and 8 mm, show that a dynamic increase in lightning impulse breakdown voltage with an increase in gap distance is associated with mineral oil and bio-based hydrocarbons. However, similar trends were not observed for synthetic ester. Calculations that allowed us to assess the impact of gap length distance on lightning impulse breakdown voltage support the observations from the experimental studies. The curves obtained in this field can be considered in the process of designing insulating systems for transformers.

Effects of case volume on short- and long-term outcomes following cadaveric lung transplantation in Japan.

Despite the low number of lung transplantations (LTs) in Japan, 10 LT facilities are accredited and good outcomes have been reported. A database review was conducted to clarify the impact of case volume at LT facilities in Japan on short- and long-term outcomes. All cadaveric LT cases treated between 2000 and 2021 in Japan were analyzed using the database of the Japanese Society of Lung and Heart-Lung Transplantation (JSLHT). The nine institutions represented were categorized into the low-volume (LV; <80 cumulative LT cases, <8 LTs/year, n=5) and high-volume (HV; ≥80 cumulative LT cases, ≥8 LTs/year, n=4) centers. Ninety-day and 1-year mortality, as well as 5- and 10-year survival data were evaluated. A total of 658 cadaveric LTs were performed at the nine institutions. The 90-day rates of mortality at the HV and LV centers were 3.5% and 3.9%, respectively (P=0.801), while the 1-year mortality rates were 9.2% and 11.5%, respectively (P=0.199). Additionally, log-rank analysis of Kaplan-Meier curves showing case volume did not reveal a significant difference in long-term survival between the HV and LV centers (P=0.272), though the LV centers had wide differences for long-term outcomes (P=0.030). Case volume did not have effects on short- or long-term outcomes following LT in Japan, while there were large variations in long-term outcomes among the LV centers compared to those of the HV centers.

Abstract TMP81: Effect of Post Thrombolytic Intracerebral Hemorrhage Volume on 90-day Outcomes in Acute Ischemic Stroke Patients

Background and Purpose: Post thrombolytic intracerebral hemorrhage (ICH) is associated with higher rate of death or disability in acute ischemic stroke patients. We investigated the relationship between post thrombolytic ICH volume and change in volume and death or disability at 90 days in acute ischemic stroke patients. Methods: We analyzed 110 patents recruited in the Safety Evaluation of 3K3A-APC in Ischemic Stroke (RHAPSODY) trial who received intravenous tissue plasminogen activator (tPA) followed by mechanical thrombectomy (if indicated) and 3K3A-APC or placebo. ICH volume was measured at Day 2 and Day 7 using susceptibility weighted sequence (SWI) on magnetic resonance imaging (MRI). We also calculated the post thrombolytic ICH volume change between Day 2 and Day 7. Outcomes were determined by using utility weighted modified Rankin scale (UW-mRs) at 90-days. We adjusted for age, gender, National Institute of Health Stroke Scale (NIHSS) score (&lt;10,10-19 and ≥20), location of hemorrhage (single basal ganglia hemorrhage, single lobar, single cerebellum, and multiple sites hemorrhage) in multivariate regression analysis. Results: A total of 88 (80%) of 110 patients had post thrombolytic ICH (mean volume 28.3 ml ± SD 62ml). The strata of ICH volume were not associated with UW-mRs at 90 days: &lt;20 cc (regression coefficient-0.05, p= 0.58), 20-39 cc (-0.23, p=0.15), or 40 cc (-0.33, p= 0.086) compared with no ICH after adjusting for potential confounders. Change in ICH volume mean volume 27.43ml ±59.01, 52 had increase in volume) between Day 2 and day 7 was not associated with UW-mRS at 90 days (regression coefficient -11.87, p= 0.796). Conclusions: We did not observe any independent effect of post thrombolytic ICH volume on death or disability in acute ischemic stroke patients. Strategies to prevent ICH expansion such as antifibrinolytic medications and reduction in ICH volume such as surgical evacuation may not reduce death or disability in acute ischemic stroke patients with post thrombolytic ICH.

Last Deglacial Environmental Change in the Tropical South Pacific From Tahiti Corals

AbstractOn glacial‐interglacial time scales, changes in the Earth's orbital configuration control climate seasonality and mean conditions. Tropical coral skeletons can be sampled at a sufficient resolution to reconstruct past seasonality. Here, last deglacial Porites skeletons from Integrated Ocean Drilling Program Expedition 310 to Tahiti are investigated and, supported by a modern calibration, monthly resolved time series in geochemical proxies (Sr/Ca, δ18O, δ13C) are constructed. For most of the deglaciation, Sr/Ca seasonality was similar to modern (0.139 ± 0.010 mmol mol−1; 2.8 ± 0.2°C) reflecting the small change in insolation seasonality. However, during the Younger Dryas, high values in Sr/Ca seasonality (0.171 ± 0.017 mmol mol−1; 3.4 ± 0.3°C) suggest a reduced mixed layer depth and enhanced influence of the South Pacific Subtropical Gyre due to South Pacific Convergence Zone (SPCZ) inactivity. Furthermore, high amplitudes in Younger Dryas skeletal δ18O (0.40 ± 0.22 ‰) and δ13C (0.86 ± 0.22 ‰) seasonality compared to modern (δ18O = 0.29 ± 0.08 ‰; δ13C = 0.27 ± 0.08 ‰) point to elevated winter‐summer discrepancies in rainfall and runoff. Mean coral Sr/Ca variability suggests an influence of Northern Hemisphere climate events, such as the Younger Dryas cooling (+0.134 ± 0.012 mmol mol−1;−2.6 ± 0.2°C), or the Bølling–Allerød warming (+0.032 ± 0.040 mmol mol−1; −0.6 ± 0.4°C). Deglacial mean coral Δδ18O (δ18Oseawater contribution to skeletal δ18O), corrected for the ice volume effect, was elevated pointing to more saline, thus dryer conditions, likely due to a northward migration of the SPCZ. Seasonal cycles in coral δ13C were likely caused by variations in linear extension rates that were reduced during the last deglaciation (1.00 ± 0.6 cm year−1) compared to today (1.6 ± 0.3 cm year−1).

Effects of bone marrow mesenchymal stromal cells-derived therapies for experimental traumatic brain injury： A meta-analysis

BackgroundBone-marrow-derived mesenchymal stromal (stem) cells [also called MSC(M)] and their extracellular vesicles (EVs) are considered a potentially innovative form of therapy for traumatic brain injury (TBI). Nevertheless, their application to TBI particularly remains preclinical, and the effects of these cells remain unclear and controversial. Therefore, an updated meta-analysis of preclinical studies is necessary to assess the effectiveness of MSC(M) and MSC(M) derived EVs in clinical trials. MethodsThe following databases were searched (to December 2022): PubMed, Web of Science, and Embase. In this study, we measured functional outcomes based on the modified neurological severity score (mNSS), cognitive outcomes based on the Morris water maze (MWM), and histopathological outcomes based on lesion volume. A random effects meta-analysis was conducted to evaluate the effect of mNSS, MWM, and lesion volume. ResultsA total of 2163 unique records were identified from our search, with Fifty-five full-text articles satisfying inclusion criteria. A mean score of 5.75 was assigned to the studies’ quality scores, ranging from 4 to 7. MSC(M) and MSC(M) derived EVs had an overall positive effect on the mNSS score and MWM with SMDs −2.57 (95 % CI -3.26; −1.88; p < 0.01) and - 2.98 (95 % CI -4.21; −1.70; p < 0.01), respectively. As well, MSC(M) derived EVs were effective in reducing lesion volume by an SMD of - 0.80 (95 % CI -1.20; −0.40; p < 0.01). It was observed that there was significant variation among the studies, but further analyses could not determine the cause of this heterogeneity. ConclusionsMSC(M) and MSC(M) derived EVs are promising treatments for TBI in pre-clinical studies, and translation to the clinical domain appears warranted. Besides, large-scale trials in animals and humans are required to support further research due to the limited sample size of MSC(M) derived EVs.

Flow front mobility of rock avalanches as a function of flow volume, grain size, channel width, basal friction and flow scale

The ability to predict the mobility of rock avalanches is necessary when designing strategies to mitigate the risks they pose. A popular mobility indicator of the flow front is the Heim’s apparent friction coefficient μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document}. In the field, μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document} shows a decrease in value as flow volume V increases. But this correlation has been a mystery as to whether it is due to a causal relationship between V and mobility since: (1) field data of μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document} do not collapse onto a single curve because typically widely scattered and (2) laboratory experiments have shown an opposite volume effect on the center of mass mobility of miniature flows. My numerical simulations confirm for the first time the existence of a functional relationship of scaling parameters where μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document} decreases as V increases in unsteady and nonuniform 3D flows. Data scatter is caused by μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document} that is affected by numerous other variables besides V. The interplay of these variables produces different granular regimes with opposite volume effects. In particular, μH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mu }_{H}$$\\end{document} decreases as V increases in the regime characterized by a relatively rough subsurface. The relationship holds for large-scale flows that, like rock avalanches, consist of a very large number of fine clasts traveling in wide channels. In these dense flows, flow front mobility increases as flow volume increases, as channel width increases, as grain size decreases, as basal friction decreases and as flow scale increases. Larger-scale flows are more mobile because they have larger Froude number values.

Development of an On-Column Trace Enrichment Method for the Determination of Sub-μg/L Bisphenol A in Bottled Water by RP-HPLC with Fluorescent Detection.

A simple extraction-free, on-column trace enrichment liquid chromatographic method for the determination of trace levels of bisphenol A (BPA) in bottled water samples has been developed. It was found possible to determine ng/L (ppt) levels of BPA by the direct introduction of 6 mL of sample water to the HPLC column utilising fluorescence detection (Exλ = 274 nm, Emλ = 314 nm). Following the loading of the sample and the chromatographic focusing of the BPA on the analytical column, a simple switch from the aqueous sample to the isocratic chromatographic elution step of 50% acetonitrile/deionised water was undertaken. Using a BPA concentration of 0.596 μg/L the effect of sample volume was investigated over the range 1.0 to 12 mL. A linear relationship with the sample volume introduced to the HPLC column and the resulting peak height for BPA was found over the entire range investigated (R2 = 0.999). Using a sample volume of 6.0 mL, a well-defined chromatographic peak was recorded for BPA over the concentration range of 0.1 μg/L to 6.25 μg/L (R2 = 0.9998). A limit of detection of 0.058 μg/L for BPA was calculated based on 3 δ. A mean recovery of 100% with an associated %CV of 7.6% (n = 5) was obtained for a bottled spring water sample fortified with 1.25 μg/L BPA. Samples can be processed in under 12 minutes, much faster than that commonly reported for conventional offline extraction and chromatographic-based methods. The results show that the optimised method holds promise for the determination of BPA in such samples.

Low-strain and ultra-long cycle stability large-diameter soft carbon microsphere potassium ion anode

Potassium-ion batteries (PIBs) with high potassium abundance, low redox potential of K/K+ and similar energy storage mechanism to lithium-ion batteries are potential candidates for large-scale energy storage in the future. However, due to the large size of K+ (1.38 Å), PIBs exhibit poor kinetics in existing commercial graphite anode materials system. Additionally, they can degrade the material structure and induce significant volume effects, leading to material fragmentation and pulverization in the process of long cycling. It is not straightforward to achieve compatibility with existing potassium anode systems, which forces us to develop new high-performance, low-strain anode materials with outstanding structural stability. Hence, nitrogen doping low-strain and large diameter soft carbon microspheres (NDCS) anodes were successfully developed to meet the demands of high-performance PIBs. Due to its large diameter and low strain characteristics, the Coulomb efficiency is as high as 98.7 %, and the capacity retention is close to 70 % after 4000 cycles at a current density of 1 A/g. Furthermore, we employed advanced computed tomography (CT) techniques to enhance the comprehension of electrochemically driven reactions from the surface to the bulk. This work provides a promising and viable technical solution for exploring PIBs anode materials with low strain and long cycling capabilities to meet the requirements of various application scenarios.

Hybrid Binder Chemistry with Hydrogen-Bond Helix for High-Voltage Cathode of Sodium-Ion Batteries.

Since sodium-ion batteries (SIBs) have become increasingly commercialized in recent years, Na3V2(PO4)2O2F (NVPOF) offers promising economic potential as a cathode for SIBs because of its high operating voltage and energy density. According to reports, NVPOF performs poorly in normal commercial poly(vinylidene fluoride) (PVDF) binder systems and performs best in combination with aqueous binder. Although in line with the concept of green and sustainable development for future electrode preparation, aqueous binders are challenging to achieve high active material loadings at the electrode level, and their relatively high surface tension tends to cause the active material on the electrode sheet to crack or even peel off from the collector. Herein, a cross-linkable and easily commercial hybrid binder constructed by intermolecular hydrogen bonding (named HPP) has been developed and utilized in an NVPOF system, which enables the generation of a stable cathode electrolyte interphase on the surface of active materials. According to theoretical simulations, the HPP binder enhances electronic/ionic conductivity, which greatly lowers the energy barrier for Na+ migration. Additionally, the strong hydrogen-bond interactions between the HPP binder and NVPOF effectively prevent electrolyte corrosion and transition-metal dissolution, lessen the lattice volume effect, and ensure structural stability during cycling. The HPP-based NVPOF offers considerably improved rate capability and cycling performance, benefiting from these benefits. This comprehensive binder can be extended to the development of next-generation energy storage technologies with superior performance.

The Effect of Intra-Catheter Air Volume on the Outcome of Intrauterine Insemination (IUI): A Clinical Trial Study

The Effect of Intra-Catheter Air Volume on the Outcome of Intrauterine Insemination (IUI): A Clinical Trial Study

Vascular endothelial glycocalyx shedding in ventilator-induced lung injury in rats

Endothelial permeability deterioration is involved in ventilator-induced lung injury (VILI). The integrality of vascular endothelial glycocalyx (EG) is closely associated with endothelial permeability. The hypothesis was that vascular EG shedding participates in VILI through promoting endothelial permeability. In the present study, male Sprague-Dawley (SD) rats were ventilated with high tidal volume (VT =40 ml/kg) or low tidal volume (VT =8 ml/kg) to investigate the effects of different tidal volume and ventilation durations on EG in vivo. We report disruption of EG during the period of high tidal volume ventilation characterized by increased glycocalyx structural components (such as syndecan-1, heparan sulfate, hyaluronan) in the plasma and decreased the expression of syndecan-1 in the lung tissues. Mechanistically, the disruption of EG was associated with increased proinflammatory cytokines and matrix metalloproteinase in the lung tissues. Collectively, these results demonstrate that the degradation of EG is involved in the occurrence and development of VILI in rats, and the inflammatory mechanism mediated by activation of the NF-κB signaling pathway may be partly responsible for the degradation of EG in VILI in rats. This study enhances our understanding of the pathophysiological processes underlying VILI, shedding light on potential therapeutic targets to mitigate VILI.