bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytoplankton biomass responses to a marine heat wave align with altered nitracline depth
Authors: Landry Michael R. , Freibott Alexandra L. , Beatty Jennifer L. , Selph Karen E.
Published: July 2024

The 2014–2015 warm anomaly (aka “the Blob”), the largest of periodic and intensifying marine heat wave (MHW) perturbations in the northeast Pacific, may provide some insight about the future warmer ocean. Here, we use mixed‐layer carbon estimates for total phytoplankton, major size classes and functional groups from 45 CalCOFI cruises to: (1) compare 2014–2015 MHW impacts in the southern California Current System to baseline estimates from 2004 to 2013 and (2) to test a space‐for‐time exchange hypothesis that links biomass structure to variability of nitracline depth (NCD). Seasonal and inshore‐offshore analyses from nine stations revealed almost uniform 2°C MHW warming extending 700 km seaward, fourfold to sixfold declines in nitrate concentration and 18‐m deeper NCDs. Phytoplankton C decreased 16–21% compared to 45–65% for Chl a, with the threefold difference due to altered C : Chl a. Among size classes, percent composition of nanoplankton decreased and picophytoplankton increased, driven by higher Prochlorococcus biomass, while Synechococcus and picoeukaryotes generally declined. Diatom and dinoflagellate C decreased in both onshore and offshore waters. Seasonally, the MHW delayed the normal winter refresh of surface nitrate, resulting in depressed stocks of total phytoplankton and nanoplankton, Synechococcus and picoeukaryotes during winter. Consistent with the space‐for‐time hypothesis, biomass variations for baseline and MHW cruises followed similar (not significantly different) slope relationships to NCD. All biomass components, except Prochlorococcus, were negatively related to NCD, and community biomass structure realigned according to regression slopes differences with NCD variability. Empirically derived biomass‐NCD relationships could be useful for calibrating models that explore future food‐web impacts in this coastal upwelling system.
Advances in targeted liquid chromatography‐tandem mass spectrometry methods for endocannabinoid and N‐acylethanolamine quantification in biological matrices: A systematic review
Authors: Amir Hamzah Khalisa , Turner Natalie , Nichols David , Ney Luke J.
Published: July 2024

Liquid chromatography paired with tandem mass spectrometry (LC‐MS/MS) is the gold standard in measurement of endocannabinoid concentrations in biomatrices. We conducted a systematic review of literature to identify advances in targeted LC‐MS/MS methods in the period 2017–2024. We found that LC‐MS/MS methods for endocannabinoid quantification are relatively consistent both across time and across biomatrices. Recent advances have primarily been in three areas: (1) sample preparation techniques, specific to the chosen biomatrix; (2) the range of biomatrices tested, recently favoring blood matrices; and (3) the breadth of endocannabinoid and endocannabinoid‐like analytes incorporated into assays. This review provides a summary of the recent literature and a guide for researchers looking to establish the best methods for quantifying endocannabinoids in a range of biomatrices.
Validity of the five‐item mental health inventory for screening current mood and anxiety disorders in the general population
Authors: Ten Have Margreet , Van Bon‐Martens Marja J. H. , Schouten Frederiek , Van Dorsselaer Saskia , Shields‐Zeeman Laura , Luik Annemarie I.
Published: July 2024

Objectives

The Mental Health Inventory (MHI‐5) is frequently used as a screener for mood and anxiety disorders. However, few population‐based studies have validated it against a diagnostic instrument assessing disorders following current diagnostic criteria.

Methods

Within the third Netherlands Mental Health Survey and Incidence Study (NEMESIS‐3), a representative population‐based study of adults (N = 6194; age: 18–75 years), the MHI‐5 was used to measure general mental ill‐health in the past month. Presence of mood (major depressive disorder, persistent depressive disorder, or bipolar disorder) and anxiety disorders (panic disorder, agoraphobia, social phobia, or generalized anxiety disorder) in the past month was assessed with a slightly modified version of the Composite International Diagnostic Interview 3.0 per the Diagnostic and Statistical Manual of Mental disorders‐5.

Results

The MHI‐5 was good to excellent at distinguishing people with and without a mood disorder, an anxiety disorder, and any mood or anxiety disorder. The cut‐off value associated with the highest sensitivity and highest specificity for mood disorder was ≤68, and ≤76 for an anxiety disorder or any mood or anxiety disorder.

Conclusions

The MHI‐5 can identify individuals at high risk of a current mood or anxiety disorder in the general population when diagnostic interviews are too time consuming.
Elastoplastic constitutive model for overconsolidated clays with an advanced dilatancy relation
Authors: Chen Kehao , Pang Rui , Xu Bin , Wang Xingliang
Published: July 2024

The dilatancy behavior of overconsolidated (OC) clays is a key factor in determining their strength and deformation characteristics. Recognizing the limitations of previous dilatancy relations for OC clays, a novel dilatancy relation is proposed that can effectively capture the changes in dilatancy point, volume dilatancy and contraction with the overconsolidation ratio (OCR). As OC clays revert to the normally consolidated (NC) state, the proposed dilatancy relation smoothly transitions to that of the modified Cam‐clay (MCC) model, ensuring a unified description of the dilatancy relation between OC and NC clays. The dilatancy relation can be easily incorporated into the constitutive model of different theoretical frameworks. Subsequently, this advanced dilatancy relation is integrated into a new elastoplastic constitutive model for OC clays within the framework of bounding surface and generalized plasticity theory. The validity of the proposed model is confirmed through drained triaxial compression and extension, undrained triaxial compression and extension, as well as complex stress path tests for clays with various OCRs, and the simulation results of the proposed model are compared with those of the SANICLAY model. The comparative analysis demonstrate that the model performs well in simulating the behavior of OC clays.
A projection‐based quaternion discretization of the geometrically exact beam model
Authors: Wasmer Paul , Betsch Peter
Published: July 2024

In the present work the geometrically exact beam model is formulated in terms of unit quaternions. A projection‐based discretization approach is proposed which is based on a normalization of the quaternion approximation. The discretization relies on NURBS shape functions and, alternatively, on Lagrangian interpolation. The redundancy of the quaternions is resolved by applying the method of Lagrange multipliers. In a second step the Lagrange multipliers are eliminated circumventing the need to solve saddle point systems. The resulting finite elements retain the objectivity of the underlying beam formulation. Optimal rates of convergence are observed in representative numerical examples.
A project‐based learning mode for science students: Fluorescent protein expression in trypanosomes
Authors: Mosquillo María Florencia , Scalese Gonzalo , Castro Felipe , Pérez‐Díaz Leticia
Published: July 2024

An effective, practical approach for incorporating molecular biology tools to biology and biochemistry students is described. For 6 weeks, students are exposed to bacterial transformation, plasmid DNA purification and analysis, parasite transfection, ectopic expression of fluorescent proteins, fluorescence microscopy, and flow cytometry analysis. This research‐oriented laboratory course delves into theoretical and practical concepts of basic techniques in molecular biology to emphasize the logical connections between the obtained results and the resolution of problems that arise daily in a research laboratory, training the students in planning, conducting, discussing, and presenting their own experiments and results.
Enhanced mechanical and interfacial performances of carbon fiber reinforced composites with low percentage of amine functionalized graphene
Authors: Choudhury Debendra Nath , Pareta Ashish Singh , Rajesh A. K. , Panda S. K.
Published: July 2024

This paper reports improvement in the tensile, flexural and interlaminar shear strength (ILSS) properties of ADG‐NH2/Epoxy/CFRP composites at low filler content. Five symmetrical CFRP composite laminates were prepared through wet layup process assisted by vacuum bagging technique with varying wt% proportions (0.25, 0.5, 0.75 and 1) of ADG‐NH2/Epoxy. Tensile tests, short beam shear test and flexural tests were carried out as per ASTM D3039, ASTM D2344 and ASTM 790‐10 respectively to assess the effect of the ADG‐NH2 functionalized nano additives on their mechanical properties. The variation in ILSS were studied for varying temperatures (room temperature, 35, 50, 75, 85, & 100°C for each type of ADG‐NH2/Epoxy wt% (neat, 0.25, 0.5, 0.75 & 1)) of ADG‐NH2/Epoxy/CFRP composites. The ILSS was enhanced up to ∼27% for 0.5 wt% of ADG‐NH2 reinforced CFRP at room temperature but reduced with the higher concentrations (0.75 wt% & 1 wt%). It was observed that ILSS reduced with gradual temperature variations up to 100°C w.r.t room temperature. But an increment was observed up to 0.5 wt% for ADG‐NH2 for all temperature. Form the test results, it has been recorded an improvement in mechanical properties that is, the elastic modulus by ∼18%, ultimate tensile strength by ∼21%, % elongation at break by∼19% and toughness by∼28% for the 0.5 wt% of ADG‐NH2 graphene nano additive reinforced CFRP composite laminates as compared to neat epoxy CFRP laminates. Results also show the augmentation in the Max load by ∼24%, flexural strength by ∼33%, flexural modulus by ∼43%, and flexural strain by ∼26% were observed for the 0.5 wt% of ADG‐NH2 graphene nano additive reinforced CFRP composite laminates as compared to neat epoxy CFRP composite laminates. Fractographic studies of fractured surface using SEM analyses shows better adhesion mechanisms which supports the augmentation in mechanical properties with addition of amine functionalized graphene to CFRP laminate.

Highlights

Reinforcement of amine functionalized (ADG‐NH2) graphene in the epoxy matrix and incorporation with carbon fibers to enhance the interfacial and flexural properties.

Evaluation of temperature effects on interlaminar shear strength properties of amine functionalized CFRP composites

Improvements in tensile, ILSS and flexural properties observed for a low percentage (0.5 wt%) of ADG‐NH2 graphene reinforced CFRP composite laminates.

Use of aerospace grade epoxy and resin with amine functionalized graphene for further use in aerospace industry applications.
Optimized lung expansion ventilation modulates ventilation‐induced lung injury in preterm lambs
Authors: Brokken Tim , Hütten Matthias C. , Ophelders Daan R. M. G. , van Gorp Charlotte , Wolfs Tim G. A. M. , Wald Martin
Published: July 2024

Introduction

Preterm infants close to viability commonly require mechanical ventilation (MV) for respiratory distress syndrome. Despite commonly used lung‐sparing ventilation techniques, rapid lung expansion during MV induces lung injury, a risk factor for bronchopulmonary dysplasia. This study investigates whether ventilation with optimized lung expansion is feasible and whether it can further minimize lung injury. Therefore, optimized lung expansion ventilation (OLEV) was compared to conventional volume targeted ventilation.

Methods

Twenty preterm lambs were surgically delivered after 132 days of gestation. Nine animals were randomized to receive OLEV for 24 h, and seven received standard MV. Four unventilated animals served as controls (NV). Lungs were sampled for histological analysis at the end of the experimental period.

Results

Ventilation with OLEV was feasible, resulting in a significantly higher mean ventilation pressure (0.7–1.3 mbar). Temporary differences in oxygenation between OLEV and MV did not reach clinically relevant levels. Ventilation in general tended to result in higher lung injury scores compared to NV, without differences between OLEV and MV. While pro‐inflammatory tumor necrosis factor‐α messenger RNA (mRNA) levels increased in both ventilation groups compared to NV, only animals in the MV group showed a higher number of CD45‐positive cells in the lung. In contrast, mean (standard deviations) surfactant protein‐B mRNA levels were significantly lower in OLEV, 0.63 (0.38) compared to NV 1.03 (0.32) (p = .023, one‐way analysis of variance).

Conclusion

In conclusion, a small reduction in pulmonary inflammation after 24 h of support with OLEV suggests potential to reduce preterm lung injury.
Long‐term lung function follow‐up of preterm infants less than 32 weeks of gestational age
Authors: Merino‐Hernández Amaia , Muñoz‐Cutillas Agustin , Ramos‐Navarro Cristina , Bellón‐Alonso Sara , Rodríguez‐Cimadevilla Juan Luis , González‐Pacheco Noelia , Rodríguez‐Fernández Rosa , Sánchez‐Luna Manuel
Published: July 2024

Background

Preterm infants, particularly those with bronchopulmonary dysplasia (BPD), are at risk of lung development problems. Over the last decades, lung protective strategies have been used, decreasing the risk of chronic lung disease.

Objective

To evaluate the pulmonary function test (PFT) of preterm infants born after the introduction of lung protective strategies and to assess perinatal determinants of impaired lung function in this population.

Methods

A prospective, observational, single‐center study was conducted in the neonatal unit of a high‐complexity hospital. The study included newborns with less than 32 weeks gestational age born between 2012 and 2014, who were followed up until they reach school age. For the main outcome, two groups were stablished: no BPD or grade 1 BPD (no BPD/1) and grade 2 or 3 BPD (BPD 2/3).

Results

Out of 327 patients, 116 were included. BPD was diagnosed in 49.1% (47), with 50.9% (29) classified as grade 1, 35.1% (20) as grade 2, and 14.0% (8) as grade 3. Mean age at PFT was 8.59 years (SD 0.90). Mean FEV1% was 95.36% (SD 13.21) and FEV1 z‐score −0.36 (SD 1.12); FVC% 97.53% (SD 12.59) and FVC z‐score −0.20 (SD 1.06); FEV1/FVC ratio 85.84% (SD 8.34) and z‐score −0.24 (SD 1.34). When comparing patients with no BPD/1 and BPD 2/3, we observed differences in all pulmonary function parameters, which persisted after adjusting for gestational age. No differences in PFT were observed between patients without BPD and those with grade 1 BPD. Most patients (76.7%, 89) had normal spirometry pattern, with obstructive pattern observed in 12.9% (15), restrictive pattern in 9.5% (11), and mixed pattern in 0.9% (1) of patients.

Conclusion

Preterm infants with BPD 2/3 showed a decrease in all pulmonary function parameters compared to preterm infants with no BPD/1; an effect that was independent of gestational age. Among patients with BPD who had an altered PFT pattern, the most common pattern was obstructive, followed by restrictive and then, mixed.
Futility Interim Analysis Based on Probability of Success Using a Surrogate Endpoint
Authors: Fougeray Ronan , Vidot Loïck , Ratta Marco , Teng Zhaoyang , Skanji Donia , Saint‐Hilary Gaëlle
Published: July 2024

In clinical trials with time‐to‐event data, the evaluation of treatment efficacy can be a long and complex process, especially when considering long‐term primary endpoints. Using surrogate endpoints to correlate the primary endpoint has become a common practice to accelerate decision‐making. Moreover, the ethical need to minimize sample size and the practical need to optimize available resources have encouraged the scientific community to develop methodologies that leverage historical data. Relying on the general theory of group sequential design and using a Bayesian framework, the methodology described in this paper exploits a documented historical relationship between a clinical “final” endpoint and a surrogate endpoint to build an informative prior for the primary endpoint, using surrogate data from an early interim analysis of the clinical trial. The predictive probability of success of the trial is then used to define a futility‐stopping rule. The methodology demonstrates substantial enhancements in trial operating characteristics when there is a good agreement between current and historical data. Furthermore, incorporating a robust approach that combines the surrogate prior with a vague component mitigates the impact of the minor prior‐data conflicts while maintaining acceptable performance even in the presence of significant prior‐data conflicts. The proposed methodology was applied to design a Phase III clinical trial in metastatic colorectal cancer, with overall survival as the primary endpoint and progression‐free survival as the surrogate endpoint.
Investigating the role of tropical and extratropical waves in the Hadley circulation via present‐day Earth‐like to globally uniform sea‐surface temperature forcing
Authors: Thakur A.B.S. , Sukhatme Jai , Harnik Nili
Published: July 2024

The tropical overturning circulation is examined in a moist aquaplanet general circulation model forced using a non‐interactive sea‐surface temperature (SST) distribution that varies between a present‐day Earth‐like profile and one that is globally uniform. A Hadley cell (HC)‐like flow is observed in all experiments along with the poleward transport of heat and angular momentum. In simulations with non‐zero SST gradients, deep convection near the Equator sets up a deep tropical cell; midlatitude baroclinic Rossby waves flux heat and angular momentum poleward, reinforcing the thermally direct circulation. As the imposed SST gradient is weakened, the HC transitions from a thermally and eddy‐driven regime to one that is completely eddy‐driven. When the SST is globally uniform, equatorial waves concentrate precipitation in the Tropics and facilitate the lower‐level convergence necessary for the ascending branch of the HC. Midlatitude Rossby waves generated near the surface become very weak, but upper‐level baroclinicity generates waves that cause equatorward transport of heat and poleward transport of momentum. Moreover, these upper‐level waves induce a circulation that opposes the time‐mean HC, thus highlighting the role of tropical waves in driving an overturning circulation that looks similar to the present‐day Earth‐like case, even for the case with globally uniform SSTs. In all cases, anomalies associated with the tropical waves closely resemble those that sum to give the upper‐level zonal mean divergent outflow. Through their ability to modulate tropical rainfall and the related latent heating, equatorial waves cause considerable hemispheric asymmetry in the HC and impart synoptic and intraseasonal variability to the tropical overturning circulation.
Single‐cell gene regulatory network analysis for mixed cell populations
Authors: Tang Junjie , Wang Changhu , Xiao Feiyi , Xi Ruibin
Published: July 2024

Gene regulatory network (GRN) refers to the complex network formed by regulatory interactions between genes in living cells. In this paper, we consider inferring GRNs in single cells based on single‐cell RNA sequencing (scRNA‐seq) data. In scRNA‐seq, single cells are often profiled from mixed populations, and their cell identities are unknown. A common practice for single‐cell GRN analysis is to first cluster the cells and infer GRNs for every cluster separately. However, this two‐step procedure ignores uncertainty in the clustering step and thus could lead to inaccurate estimation of the networks. Here, we consider the mixture Poisson log‐normal model (MPLN) for network inference of count data from mixed populations. The precision matrices of the MPLN are the GRNs of different cell types. To avoid the intractable optimization of the MPLN’s log‐likelihood, we develop an algorithm called variational mixture Poisson log‐normal (VMPLN) to jointly estimate the GRNs of different cell types based on the variational inference method. We compare VMPLN with state‐of‐the‐art single‐cell regulatory network inference methods. Comprehensive simulation shows that VMPLN achieves better performance, especially in scenarios where different cell types have a high mixing degree. Benchmarking on real scRNA‐seq data also demonstrates that VMPLN can provide more accurate network estimation in most cases. Finally, we apply VMPLN to a large scRNA‐seq dataset from patients infected with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and find that VMPLN identifies critical differences in regulatory networks in immune cells between patients with moderate and severe symptoms. The source codes are available on the GitHub website (github.com/XiDsLab/SCVMPLN).
Fixed‐time event‐dependent intermittent control for reaction‐diffusion systems
Authors: Hu Xiaofang , Wang Leimin , Zong Xiaofeng
Published: July 2024

This article discusses the fixed‐time stabilization (FxTS) problem for reaction‐diffusion systems (RDSs). First, this article designs a fixed‐time event‐dependent intermittent control strategy by introducing four nonlinear functions. The switching of the controller between the working and resting phases is no longer time‐dependent, avoiding the relatively stringent constraint on the control ratio in the existing studies of FxTS based on discontinuous‐time control. Under the presented event‐dependent intermittent control strategy, RDSs can be stabilized within a fixed time and the settling time can be estimated as the zero point of the pre‐defined nonlinear function. In contrast to the existing estimation methods, the estimation method of this article is more universal and less conservative. Moreover, this article derives several generalized stabilization criteria for RDSs under event‐dependent intermittent control employing the Lyapunov method and mathematical induction. Finally, an example is given to clarify the validity of the fixed‐time control strategy and the FxTS criteria.
Composite continuous fast nonsingular terminal sliding mode trajectory tracking control for Mars entry vehicle
Authors: Li Ting , Zhao Zhenhua , Ding Shihong
Published: July 2024

This paper presents a composite continuous fast nonsingular terminal sliding mode (CCFNTSM) trajectory tracking control method for Mars entry vehicle. Firstly, the trajectory tracking is transferred into the tracking of the pre‐designed drag acceleration. Secondly, the finite‐time disturbance observer (FTDO) is introduced to estimate the matched and mismatched disturbances. And then, the dynamical fast nonsingular terminal sliding mode manifold is designed based on the estimation information. Finally, the CCFNTSM controller is constructed and its continuity is guaranteed by employing the power function of sliding variable to replace the constant switching gain. Numerical simulation results validate the effectiveness of the proposed control method.
Highly Crystalline Multivariate Prussian Blue Analogs via Equilibrium Chelation Strategy for Stable and Fast Charging Sodium‐Ion Batteries
Authors: Wang Yichao , Liu Jiahe , Jiang Ning , Yang Jianhua , Yang Cheng , Liu Yu
Published: July 2024

Prussian blue analogs (PBAs) have been widely recognized as superior cathode materials for sodium‐ion batteries (SIBs) owing to numerous merits. However, originating from the rapid crystal growth, PBAs still suffer from considerable vacancy defects and interstitial water, making the preparation of long‐cycle‐life PBAs the greatest challenge for its practical application. Herein, a novel equilibrium chelation strategy is first proposed to synthesize a high crystallinity (94.7%) PBAs, which is realized by modulating the chelating potency of strong chelating agents via “acid effect” to achieve a moderate chelating effect, forcefully breaking through the bottleneck of poor cyclic stability for PBAs cathodes. Impressively, the as‐prepared highly crystalline PBAs represent an unprecedented level of electrochemical performance including ultra‐long lifespan (10000 cycles with 86.32% capacity maintenance at 6 A g−1), excellent rate capability (82.0 mAh g−1 at 6 A g−1). Meanwhile, by pairing with commercial hard carbon, the as‐prepared PBAs‐based SIBs exhibit high energy density (350 Wh kg−1) and excellent capacity retention (82.4% after 1500 cycles), highlighting its promising potential for large‐scale energy storage applications.
Optimizing Crystal Orientation and Defect Mitigation in Antimony Selenide Thin‐Film Solar Cells through Buffer Layer Energy Band Adjustment
Authors: Yang Yusheng , Zhang Tingyu , Zhu Hongcheng , Geng Kangjun , Huang Shan , Shen Bangzhi , Dong Boning , Zhang Shuai , Gu Ding , Jiang Sai , Yan Yan , Guo Huafei , Qiu Jianhua , Li LvZhou , Yuan Ningyi , Ding Jianning
Published: July 2024

Antimony selenide (Sb2Se3) has sparked significant interest in high‐efficiency photovoltaic applications due to its advantageous material and optoelectronic properties. In recent years, there has been considerable development in this area. Nonetheless, defects and suboptimal [hk0] crystal orientation expressively limit further device efficiency enhancement. This study used Zinc (Zn) to adjust the interfacial energy band and strengthen carrier transport. For the first time, it is discovered that the diffusion of Zn in the cadmium sulfide (CdS) buffer layer can affect the crystalline orientation of the Sb2Se3 thin films in the superstrate structure. The effect of Zn diffusion on the morphology of Sb2Se3 thin films with CdxZn1‐xS buffer layer has been investigated in detail. Additionally, Zn doping promotes forming Sb2Se3 thin films with the desired [hk1] orientation, resulting in denser and larger grain sizes which will eventually regulate the defect density. Finally, based on the energy band structure and high‐quality Sb2Se3 thin films, this study achieves a champion power conversion efficiency (PCE) of 8.76%, with a VOC of 458 mV, a JSC of 28.13 mA cm−2, and an FF of 67.85%. Overall, this study explores the growth mechanism of Sb2Se3 thin films, which can lead to further improvements in the efficiency of Sb2Se3 solar cells.
“Coir Raincoat”‐Boosted Biomimetic Hydrogel for Efficient Solar Desalination and Wastewater Purification
Authors: Nie Boli , Zhang Weiwei , Wang Yizhen , Meng Yanming , Zhao Xi , Dou Xiangyu , Wu Yan‐Chao , Li Hui‐Jing
Published: July 2024

Solar‐driven interfacial evaporation is an efficient method for purifying contaminated or saline water. Nonetheless, the suboptimal design of the structure and composition still necessitates a compromise between evaporation rate and service life. Therefore, achieving efficient production of clean water remains a key challenge. Here, a biomimetic dictyophora hydrogel based on loofah/carbonized sucrose@ZIF‐8/polyvinyl alcohol is demonstrated, which can serve as an independent solar evaporator for clean water recovery. This special structural design achieves effective thermal positioning and minimal heat loss, while reducing the actual enthalpy of water evaporation. The evaporator achieves a pure water evaporation rate of 3.88 kg m−2 h−1 and a solar‐vapor conversion efficiency of 97.16% under 1 sun irradiation. In comparison, the wastewater evaporation rate of the evaporator with ZIF‐8 remains at 3.85 kg m−2 h−1 for 30 days, which is 16.3% higher than the light irradiation without ZIF‐8. Equally important, the evaporator also showcases the capability to cleanse water from diverse sources of contaminants, including those with small molecules, oil, heavy metal ions, and bacteria, greatly improving the lifespan of the evaporator.
A Computational Fluid Dynamics and Support Vector Regression Combined Method for Predicting the Flow Performance of the Five‐Strand Tundish
Authors: Wu Di , Liu Junda , Wu Dongling , Zhou Ping
Published: July 2024

To optimize the flow field of a multistrand tundish and improve the steel quality, a prediction model integrating the techniques of computational fluid dynamics (CFD) and support vector regression (SVR) is proposed. A total of 125 cases with different structure parameters, i.e., the diameter and inclination angle of the orifices, are designed. The flow field of liquid steel in the tundish is calculated by CFD, and a sample dataset is established. Then, the SVR, combining the genetic algorithm with K‐fold, is employed to train and predict the sample dataset. In the results, it is shown that the SVR model demonstrates good learning performance on the training dataset. The average absolute errors of predictions for dead volume fraction and consistency are 0.50% and 0.71%. In addition, the SVR model takes much less computational cost than the CFD method to predict the flow performance of tundish in a given baffle structure.
Generalised component method for bolted bearing type connections
Authors: Zhou Jingsheng , Yan Shen , Zhang Hao , Rasmussen Kim J. R. , Deierlein Gregory G.
Published: July 2024

This paper develops a new generalised component method (GCM) model for bolted bearing type connections that predicts their full‐range response and all relevant strength limit states, including the bolt shear, bearing, shear‐out, net section fracture and block shear limit states. The proposed model divides a bolted bearing type connection into components that significantly contribute to its deformation and/or strength limit states. For each component, the force‐deformation curve is derived, including the post‐ultimate response, and expressed as a trilinear relationship. By assembling all components (springs) into the connection model, the multi‐linear force‐displacement response of the connection can be predicted, including the ultimate strength and ultimate deformation capacities. The proposed GCM can consider the interaction of adjacent bolts in modelling multi‐bolt connections. The new GCM is shown to accurately predict force‐displacement responses obtained from experimental tests and non‐linear finite element analyses. It is also shown to predict experimental responses significantly more accurately than the current component method implemented in Eurocode 3‐1.8.
Unsteady Aerodynamics of Delta Kites for Airborne Wind Energy Under Dynamic Stall Conditions
Authors: Castro‐Fernández I. , Cavallaro R. , Schmehl R. , Sánchez‐Arriaga G.
Published: July 2024

Three unsteady aerodynamic tools at different levels of fidelity and computational cost were used to investigate the unsteady aerodynamic behavior of a delta kite applied to airborne wind energy. The first tool is an in‐house unsteady panel method that is fast but delivers low to mid fidelity predictions. The second tool uses the open‐source CFD code SU2 to solve the unsteady Reynolds‐averaged Navier–Stokes equations with the
SST turbulence model. At an intermediate level of fidelity, a semiempirical dynamic stall model that combines the panel method with a phenomenological dynamic stall module is proposed. The latter has free parameters that are fine‐tuned with CFD results from the second tool. The research on the dynamic stall model has been inspired by two flight test campaigns suggesting dynamic stall phenomena possibly driven by the periodic variation of the angle of attack (aerodynamic pitching motion) during crosswind maneuvers. The recorded inflow along the flight path was prescribed in the three aerodynamic tools. As expected, the price to pay for the low computational cost of the panel method is its inability to capture the dynamic stall phenomenon. The results from unsteady CFD qualitatively matched the experimental data identifying a leading‐edge vortex that forms and detaches cyclically during the pitching motion. Using RANS data, the semiempirical tool was fined‐tuned to reproduce the dynamic stall behavior, becoming an accurate and fast aerodynamic tool for coupling with any kite flight simulator. Further discussions on the effects of kite aerostructural deflections are included.
Technology of SS-OCT Biometer: Argos Biometer
Authors: Chong Changho
Published: July 2024

Swept-source OCT captures an image of the whole eye from the cornea to the retina prior to cataract surgery. The measured image is used to calculate the biometric parameters necessary for IOL power calculation. Swept-source OCT technology allows two-dimensional imaging, a superior signal-to-noise ratio, and improves tissue penetration and image quality. The Argos biometer calculates axial length as the sum of physical distances of four segments: central corneal thickness, aqueous depth, lens thickness, and the thickness of vitreous humor, each calculated by dividing optical distance by corresponding refractive indices (1.375, 1.336, 1.41, 1.336) at infra-red wavelength range which implies the true physical scale of AL. The performance of the Argos biometer includes an enhanced retinal visualization, segmented axial length measurement, and enhanced OCT keratometry.
ANTERION Swept-Source OCT Biometer
Authors: Schröpfer Jana , Cornwell Richard , Gunkel Sandro , Polzer Melanie , Thomson Steven
Published: July 2024

This chapter is a full description and analysis of the technology behind the Heidelberg ANTERION SS-OCT optical biometer. It includes a complete description of how it works for biometry measurements including demonstrations of high-resolution scans that can be obtained and their clinical applications such as for phakic IOL implantation and macular evaluation. There is a complete description of the corneal topography capabilities as well as the determination of corneal power. Anterior chamber angle and metrics are also described. There is a complete description of IOL power capabilities and how to use the IOL power prediction software in the instrument.
The Pentacam Family
Authors: Iwanczuk Jörg
Published: July 2024

The ongoing development of the Pentacam, from its origins in 2002 to the latest version (the Pentacam AXL Wave), is described. Today, the Pentacam AXL Wave combines Scheimpflug imaging, partial coherence interferometry, a Hartmann–Shack wavefront sensor and retroillumination. It enables an assessment of the total eye visual performance, including objective refraction and high-order aberration analysis, and a true separation of the internal wavefront from the total corneal wavefront (not possible with Placido technology).

The many features of the Pentacam family are illustrated, with specific attention to the IOL power calculation formulas available for unoperated and post-corneal refractive surgery eyes, as well as for eyes requiring toric IOLs to correct corneal astigmatism.
Exact Optics
Authors: Alda Javier
Published: July 2024

The geometrical and physical models of optics describe the behavior of light in image-forming optical systems. In this chapter, we first analyze the limitations and constraints of paraxial geometrical optics and describe geometrical aberrations. Optical aberrations can be expressed in terms of wavefront aberrations due to the wave nature of light. Hence, this model provides us with figures of merit that describe the quality of optical systems in terms of their capability to produce faithful images. As a consequence, we will show how diffraction ultimately limits the performance of optical systems. We will analyze the human eye as an example to understand this model further. These formalisms can generate personalized models of the eye—if we include patient’s parameters obtained from aberrometers, corneal topography, and pachymetry—and guide the selection of intra-ocular lenses for optimum visual performance.
Emmetropia Verifying Optical (EVO) Formula
Authors: Yeo Tun Kuan
Published: July 2024

The origins of the Emmetropia Verifying Optical (EVO) formula (versions 1.0 and 2.0) are described. This is a thick lens formula based on Gaussian optics principles; it considers the anterior and posterior corneal curvatures, central corneal thickness, as well as the geometry of the intraocular lens (IOL). The formula modifies the axial length measured by optical biometry, calculates the total corneal power using Gaussian thick lens equations and calculates the principal planes of the IOL based on its geometry. The performance of the EVO formula, its toric calculator and the formula version for post-myopic laser vision correction eyes are reported in a review of published papers.
OKULIX Raytracing Software
Authors: Preußner Paul-Rolf
Published: July 2024

The raytracing software package OKULIX was initially developed for scientific purposes in the context of accommodating IOLs. Later it was extended to corneal laser surgery which is still available in the “corneal module” of OKULIX. The latest development was then the application to IOL calculation. One of the essential guidelines of the software development was to reduce universal applicability (unlike as in other commercially available raytracing software) in order to optimize it to the special situation of a human eye, i.e., concentration of the fovea as the only optical area of interest, and restriction to mostly four but in maximum six refracting surfaces. In addition, the collection of the manufacturer’s blue prints of the big majority of IOL models on the market was necessary, including continuous updates. In general, the result is an IOL calculation software that is based on physical rather than on statistical data to the highest possible extent, applicable to all kinds of eyes, even without knowing their history. Other than in most IOL formulas, missing information is not taken from Gullstrand’s but from Liou and Brennan’s eye model. The accuracy of OKULIX IOL calculations has been proven to be never systematically worse compared to other methods when the same measured input data are used.
The PEARL-DGS Formula
Authors: Debellemanière Guillaume , Saad Alain , Gatinel Damien
Published: July 2024

The PEARL-DGS formula is a thick lens formula that uses AI techniques to predict the distance between the posterior corneal surface and the anterior IOL surface (“theoretical internal lens position,” TILP). The TILP value was back-calculated from refractive outcome in a large dataset. The refractive index values used in the formula are those of the Atchison eye model, except for the corneal index, which was determined empirically during the formula development process. In our case, this value was 1.363. The performance of the formula was evaluated in different studies with a high level of precision and accuracy, comparable to the latest formulas in the field.
SRK Formula History
Authors: Retzlaff John , Sanders Donald R.
Published: July 2024

This is a complete history of the formulation and development of the SRK family of formulas by Drs. Sanders, Retzlaff, and Kraff from the original SRK I in 1980 to the final SRK/T in 1990 including all the travails that led to their development.
Calculation of Phakic and Pseudophakic Additional Lenses
Authors: Langenbucher Achim , Cayless Alan , Schrecker Jens
Published: July 2024

Calculation of add-on intraocular lens (IOL) power, both for phakic and pseudophakic eyes, can be done based on refraction, spectacle vertex distance, corneal curvatures, and IOL plane position. In this chapter, a Gaussian optical matrix formalism is described allowing for the calculation of IOL power and lateral magnification. This method is based on a system matrix, which describes and characterizes the paraxial optical properties of the relevant optical part of the eye. This system matrix is composed of a product of refraction and translation matrices. The power of non-toric and toric lenses can be calculated in this way. The power and magnification of non-toric add-on lenses can also be easily estimated with a polynomial linear model.
Astigmatism Notation: Dealing with Vectors
Authors: Næser Kristian
Published: July 2024

Net astigmatisms and spherocylinders are complex formats with magnitudes in diopters and directions in degrees. Both magnitudes and directions entities must be converted to vectors to allow for any kind of calculation. This chapter describes the principles for conversion of corneal and refractive data to dioptric vectors. Næser’s polar value dioptric vectors are detailed and other dioptric vector formats (Thibos, Holladay and Lang’s power matrix) are reviewed. The appropriate statistical methods for univariate and bivariate analysis are described, a terminology is suggested, and practical calculations are demonstrated.
Lens and IOL Tilt
Authors: Hirnschall Nino , Findl Oliver
Published: July 2024

Tilt can be quantified by two principal methods either by cross-sectional scans of the anterior segment such as Scheimpflug imaging, optical coherence tomography (OCT), and ultrasound biomicroscopy (UBM), or by assessing the Purkinje reflexes. IOL tilt affects the visual quality, the final refraction, and the amount of residual astigmatism. Tilt accounts for more than 10° of the error in toric IOL power calculation and this value increases to almost 20%, if combined with angle kappa. Predicting tilt and taking it into account would significantly improve toric IOL power calculation. The factors influencing tilt include the capsulorhexis, pseudo-exfoliation, IOL material and design, after-cataract changes, and combined surgeries.
Out-of-the-Bag Implantation IOL Power
Authors: Aramberri Jaime
Published: July 2024

In the absence of a safe capsular support, the IOL will be implanted out-of-the-bag. There are different anatomical locations where a posterior chamber IOL can be implanted: sutured to iris, ciliary sulcus supported, or fixated to the sclera with or without sutures. All of them entail a change in the IOL effective power that has to be calculated by the surgeon to avoid a final refractive error. In this chapter, several sources of error are extensively analyzed and the most precise methods to correct them are clearly exposed. Moreover, there are various IOL models designed specifically for out-of-the bag implantation: anterior chamber, iris claw, and scleral fixated. Each of them, with their own clinical and optical features must be mastered in order to achieve an accurate power calculation.
An EFT approach to baryon number violation: lower limits on the new physics scale and correlations between nucleon decay modes
Authors: Bas i Beneito Arnau , Gargalionis John , Herrero-García Juan , Santamaria Arcadi , Schmidt Michael A.
Published: July 2024

Abstract

Baryon number is an accidental symmetry of the Standard Model at the Lagrangian level. Its violation is arguably one of the most compelling phenomena predicted by physics beyond the Standard Model. Furthermore, there is a large experimental effort to search for it including the Hyper-K, DUNE, JUNO, and THEIA experiments. Therefore, an agnostic, model-independent, analysis of baryon number violation using the power of Effective Field Theory is very timely. In particular, in this work we study the contribution of dimension six and seven effective operators to |∆(B − L)| = 0, 2 nucleon decays taking into account the effects of Renormalisation Group Evolution. We obtain lower limits on the energy scale of each operator and study the correlations between different decay modes. We find that for some operators the effect of running is very significant.
Scattering amplitudes and the Cotton double copy
Authors: Emond William T. , Moynihan Nathan
Published: July 2024

Abstract

We construct classical curvature spinors in topologically massive gauge theory and topologically massive gravity, expressed in terms of massive three-particle amplitudes. We show that when the amplitudes double copy, the curvature spinors associated with particular solutions satisfy the Cotton double copy, the three-dimensional cousin of the Weyl double copy. Furthermore, we show that under certain circumstances the Cotton double copy can be derived via a dimensional reduction of the Weyl double copy.
Eversible tentacle organs in caterpillar–ant communication: do they signal partner quality in polyommatinae lycaenid butterflies?
Authors: Fiedler Konrad
Published: July 2024

In mutualistic associations, lycaenid butterfly caterpillars trade nectar secretions against protective services by ants. Eversions of paired abdominal tentacle organs (TO) have been suggested to honestly signal nectar secretion capacity of caterpillars to their ant visitors. Using data from 1561 staged encounters between larvae of nine West Palaearctic Polyommatinae species and worker ants of three species, I show that within experimental series, significantly positive correlations between TO eversion and nectar secretion rate emerged only sporadically (12 of 50 series). In a meta-analysis integrating over all tested species combinations and experimental conditions, the relationship between nectar secretion and TO eversion rate was weak (r2 = 6.6%), though significantly positive. This association between myrmecophilous behaviours was not stronger in experiments with feeding mature larvae than in prepupal non-feeding larvae; however, the latter delivered distinctly more nectar. Relationships between nectar secretions and TO eversions were independent of the density of ant partners available and did not vary consistently between lycaenid species showing different levels of myrmecophily. When mean values of nectar secretions per experimental series were related to the respective mean TO eversion rates, a clear positive relationship only emerged among intimately ant-associated species. In moderate myrmecophiles average tentacle activity was unrelated to mean nectar delivery. Overall, these experiments yielded only weak support for the reliable-signalling hypothesis. I propose that TO eversions rather serve as complementary dimension of multimodal communication between partners. ‘Apparent honesty’ may then emerge if caterpillars achieve optimal ant attendance by concomitantly increasing nectar secretion and TO eversion rates.
Extent and survival of zoned pyroxene within intrusions hosting magmatic sulfides: Implications for zoned pyroxene as a prospectivity indicator
Authors: Schoneveld Louise , Barnes Stephen J. , Luolavirta Kirsi , Hu Siyu , Verrall Michael , Le Vaillant Margaux
Published: July 2024

Chromium-zoning patterns in pyroxene from the economically significant Ni-Cu sulfide deposits at Nova-Bollinger (Western Australia) and Kevitsa (Northern Finland) were investigated using XRF mapping, automated mineralogy, and EPMA analyses. At Nova-Bollinger, complex Cr-zoning patterns are found widely throughout the cumulus orthopyroxene and clinopyroxene within the Lower Intrusion, a small chonolith that hosts the vast extent of the sulfide mineralisation. Cumulus pyroxenes with visible sector and abrupt zonation patterns have been found up to 150 m vertically away from the massive sulfide ore. Complex zoning patterns are observed throughout the Kevitsa intrusion, in the form of strong oscillatory zoning in cumulus clinopyroxene and sector zoning in idiomorphic orthopyroxene oikocrysts. Kevitsa pyroxenes show varying degrees of hydration, leading to epitaxial replacement by amphibole. Cr zonation is visible through the early stages of this alteration, with preservation enabled by the presence of Cr-rich epitaxial amphibole; however, the remnant zoning is lost as the amphibole alteration progresses. Results suggest that Cr zonation in pyroxene may be an effective indicator of dynamic recharged conduits and therefore an indicator of favourable conditions for metal enriched magmatic sulfide ore formation. Such indicators have significant vertical extent from the ore body and can survive partial alteration, which makes them a useful tool for prospectivity assessment of drilled intrusions. Furthermore, our data show that there is potential for complexly zoned pyroxene to be used as an ex-situ prospectivity indicator in glacial till.