bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure and Mechanical Performance of X120 Linepipe Steel in High-Pressure Hydrogen Gas
Authors: Wang Yiyu , Feng Zhili , Wang Yanli , Ronevich Joseph , Agnani Milan , San Marchi Chris
Published: November 2024

Hydrogen-induced degradation, especially hydrogen-assisted fatigue, and fracture, must be carefully considered to maintain reliability and structural integrity of steel pipelines in gaseous hydrogen service. Additionally, the susceptibility of steels to hydrogen is well documented to be sensitive to the strength of the steel. Therefore, high strength pipeline steels with yield strength greater than 600 MPa, such as X100 and X120, must be evaluated to assess their susceptibility to hydrogen embrittlement. In this work, microstructure and mechanical properties, including the fatigue crack growth rate and fracture toughness in high-pressure hydrogen gas at a pressure of 1000 bar (105 MPa), of an as-received X120 steel were experimentally investigated. The results show the fatigue crack growth rates in gaseous hydrogen of this X120 steel follow the ASME design curves for hydrogen from the Boiler and Pressure Vessel Code Section VIII, Section 3 Code Case 2938-1. The fracture resistance in 1000 bar hydrogen gas is 43 MPa·m1/2, which is higher than approximately 30 MPa·m1/2 reported for Cr-Mo and Ni-Cr-Mo pressure vessel steels with the similar tensile strength level (approximately 950 MPa). Multi-scale metallurgical analyses were conducted to characterize the underlying microstructural features contributing to the higher fracture toughness of X120 compared to the Cr-Mo and Ni-Cr-Mo steels. The characterization shows a fine bainitic microstructure (grain size: 1 μm) and fewer carbides, characteristics created by the thermo-mechanically controlled processing (TMCP) and a lower carbon content, respectively. These features likely provide a higher fracture resistance in gaseous hydrogen compared to the traditional tempered martensitic microstructure of pressure vessel steels with greater carbon contents. A fractography analysis on the tested X120 specimens was also conducted to further reveal its fracture characteristics under high-pressure hydrogen gas. Both fatigue and fracture surfaces exhibit mainly quasi-cleavage cracks. Secondary cracks propagated in a mixed intergranular and transgranular mode. The fracture surface is much coarser and has deeper secondary cracks than that in the fatigue region.
Load Carrying Capacities of Small-Diameter Pipe Bends Under Internal Pressure: Analytical and Computational Predicitions
Authors: Robinson Nicholas , Wang Xin , Wasiluk Bogdan
Published: November 2024

The performance and embedded conservatism of common modeling approaches used for predicting load carrying capacities were evaluated for small-diameter pipe bends typically found in CANDU reactors. Comprehensive analyses were conducted using both an analytical approach and detailed finite element modelling with commercial code ABAQUS. Small diameter pipe bends, with and without local wall thinning, under loading by internal pressure were investigated. The adopted modelling approach incorporated variability in pipe bend geometry and the characterization of material properties.

The results obtained indicate that load carrying capacities of small-diameter pipe bends, either with or without local wall thinning but characterized by uniform wall thickness and single parameter material strength are conservatively predicted with analytical models in principle based on the limit load approach. However, detailed finite element modelling is needed for obtaining more accurate predictions of plastic instability pressure for pipe bends with local wall thinning.

The reported investigation provides technical insights into the modelling approaches presently used for predicting load carrying capacities of small-diameter pipe bends under internal pressure loading; in addition, it has explored embedded conservatism while recognizing the existence of involved uncertainties. The results obtained emphasize the importance of detailed characterization of pipe bend thickness and material strength in such engineering predictions.

This work has been performed under Canadian Nuclear Safety Commission (CNSC) Research and Support (R&S) project R765.1. The insights obtained may be used to further assess embedded conservatism in fit for service evaluations of CANDU outlet feeders experiencing wall thinning due to Flow Accelerated Corrosion (FAC). In addition, supplementary information informs the activities related to lowering the minimum required thickness below 75% of a straight pipe thickness by Article NB-3640 of Section III of the ASME B&PV Code for design pressure.
Comparison Between Fatigue and Fracture Behavior of Pipeline Steels in Pure and Blended Hydrogen at Different Pressures
Authors: Agnani Milan , Ronevich Joseph A. , San Marchi Chris
Published: November 2024

Existing natural gas (NG) pipeline infrastructure can be used to transport gaseous hydrogen (GH2) or blends of NG and hydrogen as low carbon alternatives to NG. Pipeline steels exhibit accelerated fatigue crack growth rates and reduced fracture resistance in the presence of GH2. The hydrogen-assisted fatigue crack growth (HAFCG) rates and hydrogen assisted fracture (HAF) resistance for pipeline steels depend on the hydrogen gas pressure. This study aims to correlate and compare the HAFCG rates of pipeline steels tested in two different gaseous environments at different pressures; high-purity hydrogen (99.9999 % H2) and a blend of nitrogen with 3% hydrogen gas (N2+3%H2). K-controlled FCG tests were performed using compact tension (CT) samples extracted from a vintage X52 (installed in 1962) and a modern X70 (2021) pipeline steel in the different gaseous environments. Subsequently, monotonic fracture tests were performed in the GH2 environment. The HAFCG rates increased with increasing GH2 pressure for both steels, in the ΔK range explored in this study. Nearly identical HAFCG rates were observed for the steels tested in different environments with equivalent fugacity (34.5 bar pure GH2 and 731 bar Blend with 3%H2). The fracture resistance of pipeline steels was significantly reduced in the presence of GH2, even at pressure as low as 1 bar. The reduction in HAF resistance tends to saturate with increasing GH2 pressure. While the fracture resistance of modern steel is substantially higher than vintage steel in air, in high pressure GH2, the HAF resistance is comparable. Similar HAF resistance values were obtained for the respective steels in the pure and blended GH2 environment with similar fugacity. This study confirms that fugacity parameter can be used to correlate HAFCG and HAF behavior of different hydrogen blends. The fracture surface features of the pipeline steels, tested in the different environments are compared to rationalize the observed behavior in GH2.
In-Situ and Ex-Situ Studies on the Morphology Changes of Polymer Pipeline Materials for Use in Hydrogen Gas Environments
Authors: Simmons Kevin , Ko Seunghyun , Kuang Wenbin , Qiao Yao , Shin Yongsoon , Han Kee Sung , Menon Nalini
Published: November 2024

The US natural gas infrastructure is a national asset that could be used to deliver hydrogen and hydrogen blends of natural gas as a pathway to reduce carbon emissions. The distribution system comprises nearly 50% plastic pipe composed of medium- and high-density polyethylene materials (MDPE and HDPE). While these materials perform adequately for natural gas, research on their hydrogen compatibility is essential to understand if any immediMDPEate and long-term risks are associated with hydrogen addition. The Blended Gas CRADA, a HyBlend project, has established a comprehensive test method for evaluating MDPE and HDPE of various plastic resin compositions of pipeline material in pure hydrogen and 20% hydrogen/80% methane blends. Both in-situ and ex-situ measurements were performed to capture hydrogen-induced changes in the polyethylene material’s crystalline, amorphous, and interphase regions.

We investigated MDPE and HDPE pipeline materials made from different polymer resin systems to evaluate the effects of hydrogen gas. The materials were characterized by their density, diffusion coefficient, free volume ratio, and degree of crystallinity. Various advanced characterization methods, including in-situ high-pressure NMR, ex-situ XRD, ex-situ DSC, and ex-situ TDA, were used to analyze the effects of changes in crystalline, amorphous, and interphase regions due to gas exposure. Time-dependent post-decompression quasi-static tensile tests were conducted to explore the effects of gas exposure time on the mechanical behavior of the pipe materials.

This work will highlight the time sensitivities during and after gas exposure. The correlation between gas-induced polyethylene morphology changes and the associated material performance will be addressed for the intended applications. These studies will show that polyethylene resin composition and material exposure are important factors when considering whether hydrogen gas affects pipeline materials positively or negatively.
Residual Stress Measurements and Modelling of Clad-Weld Interfaces
Authors: Pellereau Benjamin , Greensmith Robert , Tanner David , Goulding Mark
Published: November 2024

Residual stresses from welding are often a significant loading in defect tolerance assessments. Evaluation procedures such as R6 provide bounding Weld Residual Stress (WRS) profiles for typical component geometries which may be used if little or no information is available. However, these are often highly conservative, especially for components which receive a stress-relieving Post-Weld Heat Treatment (PWHT).

Profiles developed from Finite Element (FE) modelling and/or WRS measurements may be used if they are available. However, modelling can be time and computationally expensive as well as hard to verify. Additionally many measurement techniques are destructive so cannot be deployed on production items. To address these limitations a combination of modelling and measurements is recommended in order to verify the modelling and to address any difference between the actual component and the test piece used for the measurements.

One area which has been identified as a gap in the literature is residual stress values at the intersection between a through-wall structural weld and internal weld-deposited cladding. This paper presents modelling and measurement results from two such locations. The first location is a low alloy steel pressure vessel circumferential weld that is subsequently clad using weld deposited Alloy 82. The second is a nozzle to safe-end transition weld at which the ferritic portion of the nozzle is also clad. Where possible results of both are presented before and after PWHT.

The modelling was carried out in Abaqus with axisymmetric models of the actual component geometry using the Abaqus Weld Interface, solid state phase transformation effects were not included. Measurements were made using Deep Hole Drilling (DHD) at key locations in simplified but representative components that were manufactured as part of the weld qualification process.

At the circumferential weld there is good agreement in the shape of the predicted WRS profiles for both hoop and axial stresses. The magnitudes are also similar, although the simplifying assumptions in the modelling generate some differences, particularly at the clad-parent interface. A similar trend is seen in the safe-end weld.
Critical Strain in Carbon Steel Pipes With Local Wall Thinning Subjected to Large Bending in Soil Liquefaction-Induced Lateral Spreading
Authors: Homma Tomoka , Onuki Shoma , Imai Yasuhito , Mitsuya Masaki
Published: November 2024

A buried pipeline may undergo large bending deformations due to lateral spreading induced by soil liquefaction during an earthquake. Furthermore, the deformability of the pipeline is influenced by local wall thinning, which can result from phenomena such as corrosion. Therefore, this study examined the bending fracture behavior and critical strain of wall-thinned pipes subjected to bending moments. Bending tests were conducted on straight pipes with wall thinning located in either the compressive or tensile side in order to obtain failure modes. The experimental results showed two failure modes: buckling and rupture. Buckling failure occurred on the compressive side without the occurrence of necking in the region with localized wall-thinning. Rupture failure occurred at the area of localized wall-thinning on the tensile side. Finite elements analysis (FEA) was performed to simulate the fracture behaviors observed in the bending tests. As a result, the critical strain of the pipe exceeded 30% equivalent plastic strain for buckling mode on the compressive side and exceeded 10% equivalent plastic strain for rupture mode on the tension side. Additionally, this study offers instances of acceptable wall-thinning sizes of pipelines subjected to large bending in liquefaction-induced lateral spreading, using the criteria of 30% equivalent plastic strain on the compressive side and 10% equivalent plastic strain on the tension side.
Numerical Study on Failure Length Evaluation of Buried Continuous Pipelines Crossing Strike-Slip Faults
Authors: Hsu Wei-Hung , Chai Juin-Fu , Yang Hsuan-Chih , Chang Che-Yu , Chang Wei-Kuang
Published: November 2024

Buried pipelines are commonly used to carry water, oil and natural gas. The length of buried pipelines often extends thousands of meters. Inevitably there is a high probability that the pipeline will cross the seismic faults, especially in countries with seismic zones. Once an earthquake occurs and leads to the permanent displacement of the ground, the buried pipelines may fail or be damaged. This will affect the operation of social and economic activities. Therefore, the pipelines play an important role in societies, industries and economies, and are often referred to as lifelines. So far, the post-earthquake walkdown and inspections have been standard operation procedure for supplier of water, oil and natural gas. Through the visits and inspections, pipe segment with leaking contents or damage might be found and can be discovered and repaired immediately. For those pipe segments with severe deformation but no leakage or damage, it is difficult to find them through the walkdown and inspections. The purpose of this study is to use numerical approaches to find out the relationship between the pipeline failure length and the fault displacement of strike-slip faults for various sizes of pipelines. The research results can provide reference for water, oil, and natural gas suppliers, and can develop a more reliable post-earthquake inspection mechanism to identify pipe segments those are on the verge of failure.
Research on Pitting Evaluation of Process Pipeline Based on Extreme Value Distribution Model
Authors: Chen Liangchao , Li Haopeng , Lu Xinyuan
Published: November 2024

Frequent incidents of corrosion leaks in petrochemical process piping due to pitting corrosion necessitate a scientific assessment of the distribution patterns and maximum degree of corrosion. Such assessments are crucial for identifying potential corrosion risks and ensuring the safe and stable operation of the equipment. This paper presents a method for evaluating the extreme values of process piping corrosion based on inspection data, which includes the following steps: acquiring corrosion data, modeling and predicting extreme values with the model, and assessing pipeline corrosion. Initially, systematic thickness measurements are taken at specific points along the pipeline to compile a dataset of corrosion-related metal thinning. Subsequently, a Generalised Extreme Value (GEV) distribution model is fitted to the thinning data, and its parameters are estimated using the method of maximum likelihood to obtain a model that represents the extreme value distribution of pitting corrosion in the pipeline. Finally, by using this model, predictions are made about the maximum corrosion loss of the pipeline, which in turn allows for an assessment of the corrosion rate and remaining life of the pipeline sections. This paper focuses on a particular petrochemical process piping system, constructing a GEV model and performing a pitting assessment. Validation with actual measurements shows that the distribution of pitting corrosion in the pipeline is consistent with the GEV model. The average relative error of the prediction is 0.07, which indicating a high degree of accuracy.
High Acceleration Shaking Tests Considering Couple of Pipe Support Structure and Box Culvert
Authors: Sakai Michiya , Sakai Toshiaki , Watanabe Tatsumasa , Ono Yohei , Shimazu Ryuya
Published: November 2024

This research investigates both structural integrity and equipment functionality, aiming to improve the seismic fragility evaluation of sea water ducts by incorporating the coupling of structures and equipment, which is an approach not previously considered. Vibration tests were conducted using a high-acceleration shaking table installed at the Central Research Institute of Electric Power Industry, capable of performing tests with a maximum acceleration of 20G. Two types of specimens were prepared: one featuring a single box culvert frame, and the other incorporating a box culvert with an internal piping support structure. High-acceleration shaking tests on the box culverts revealed damage attributed to bending deformation of the sidewalls, ultimately leading to failure due to low-cycle fatigue of the reinforcing bars. In the case of the box culvert with a pipe support structure inside, damage data resulted from the coupled behavior between the pipe support structure and the box culvert.
Stress Detection of X80 Pipeline Based on Vibration Characteristics Analysis
Authors: Li Jinzhou , Liu Xiaoben , Zhang Hong
Published: November 2024

The operational environment of long-distance oil and gas pipelines is characterized by its complexity, which can lead to stress concentration and localized defects over time, consequently increasing the operational risks. One emerging technology for evaluating the structural integrity of these pipelines is non-destructive testing based on vibration characteristics. This paper elucidates the operating principle of knock detection technology. Utilizing X80 pipeline steel, we establish a finite element model for knock detection and reveal the relationship between pipeline stress state and vibration acceleration signals from small plate specimens. To validate the reliability of the finite element model, we conduct knock detection experiments under uniaxial tension. Building upon this foundation, we delve into the vibration response characteristics of small pipes under various stress conditions. Our results demonstrate a strong concurrence between the outcomes from small plate specimens and small pipes, with a close correlation between intrinsic vibration frequency and pipeline stress in vibration acceleration signals. These findings serve as a crucial stepping stone for the practical application of knock detection methods based on vibration characteristics. It is established that this method can effectively assess the stress state of X80 pipeline steel and represents a dependable approach for evaluating the serviceability of pipelines.
Study of Error Analysis and Optimization Algorithm for IMU-Based Pipeline Bending Strain Detection Through Finite Element Simulation
Authors: Shi Tong , Xie Ting , Zhang Hong , Li Rui , Ning Fangwei , Feng Qingshan , Huang Qiyu , Liu Xiaoben
Published: November 2024

Inertial Measurement Unit (IMU) sensors are capable of collecting parameters such as heading and orientation angles during pipeline navigation. Subsequently, by performing calculations, pipeline strain can be obtained, making IMU technology essential for detecting pipeline bending strains. However, during IMU-based internal inspection system operations, issues like abnormal vibrations and trajectory deviations can introduce disturbances, rendering IMU data unsuitable for direct interpretation as actual pipeline strain. This study establishes a reconstitution and simulation model for IMU-based internal inspection systems, eliminating interference from abnormal vibrations. This enables the acquisition of vibration-free pipeline bending strain data at different offset levels. Error analysis and strain mapping studies are conducted to compare reconstituted simulation data with actual pipeline strain data. An optimized algorithm is proposed to calculate pipeline bending strain, with the aim of reducing strain detection errors caused by trajectory deviations during inspections. Research findings reveal that as strain increases, deviations in the IMU-based internal inspection system’s central trajectory result in a growing disparity between detected strain and actual pipeline strain. The proposed algorithm effectively mitigates strain errors arising from inspection system trajectory deviations. This IMU’s simulation model and optimization algorithm form a technical foundation for obtaining accurate pipeline strain using IMU-based inspection data.
Computational Fluid Dynamics Approach to Evaluate Jet Impingement Loads Due to Rupture of High Energy Pipes in Nuclear Reactors
Authors: Qureshy Ali M. M. I. , Hassan M. Safy , Elzaabalawy Assem , Aboulella Mohamed , Khan Qasim , Mekky Waleed
Published: November 2024

Accurate evaluation of jet impingement loads due to pipe ruptures is crucial for nuclear power plant design and safety analysis. These loads can cause catastrophic damage to neighboring components. Although jet impingement models exist in the literature, additional effort is required to overcome their inaccuracy and non-conservatism. In the current study, an evaluation of the jet impingement loads due to a full guillotine rupture in a high energy pipeline is investigated using Computational Fluid Dynamics (CFD). The model represents a higher fidelity approach to better assess the postulated pipe rupture and its effect on neighboring pipelines. Specifically, a 3D multiphysics ANSYS Fluent model is developed to simulate the rupture of the selected pipes. The model accounts for the multiphase nature of the problem by including heavy water liquid, heavy water vapor, and surrounding air. Moreover, the model accounts for a number of highly coupled physical processes including turbulence, multiphase interactions, flashing, and heat transfer. The results show that the model can accurately predict the jet behavior and characteristics. Additionally, the results indicate a direct relationship between the diameter of the ruptured pipe, rupture area, and the magnitude of impingement loads. Specifically, larger diameters and rupture areas correlate with increased jet impingement loads, while greater distances between pipes result in decreased loads. These observations are pivotal for designing robust systems capable of withstanding varied impingement scenarios.
Statistical Analysis of Multiple Encoded Ultrasonic Testing Data Sets
Authors: Houston Eric , Parker Stephen , Keene Douglas
Published: November 2024

Localized corrosion, commonly referred to as “pitting,” in carbon steel piping systems has a significant financial and regulatory impact on commercial nuclear power plants. Quantifying the level of degradation and identifying locations which may violate the minimum wall thickness requirements or leak is an ongoing task at most, if not all, sites. Utilizing historic inspection data to predict the current and future state of a piping system is challenging without a robust definition of a pit. Work has recently been conducted by Parker, Roukema, and Patten to define “pitting” in geometric terms as it relates to localized wall loss due to corrosion in carbon steel piping [1]. The authors presented a novel approach to identifying the non-uniform pipe wall as a “pit” at discrete locations. As the authors note, the limited data set restricted the applicability of the paper’s conclusions to only the Service Water system for which the data was obtained.

This paper expands upon the previous work by increasing the number of data sets evaluated and includes additional sites with varying water chemistry and operating history. The paper utilizes a slightly simplified analysis of localized corrosion to identify the number of pits within an encoded ultrasonic thickness data set. The objective of this paper is to determine if the set of geometric characteristics proposed in the previous work can be reasonably applied to a more diverse set of piping systems.
Metallurgical and Fracture Toughness Variability Characterization of 2.25Cr 1 Mo Plate Steel for Hydroprocessing Reactors
Authors: Acuna Andres , Melfi Teresa , Penso Jorge , Wim Bennik
Published: November 2024

Fracture toughness and temper embrittlement susceptibility are pivotal factors influencing the mechanical integrity of hydroprocessing reactors within oil refineries and chemical plants. Moreover, they exert a notable impact on the minimum allowed pressurization temperature (MPT), thereby affecting the startup and shutdown times. Enhanced fracture toughness at low temperatures and heightened resistance to temper embrittlement lead to a lower permissible MPT setting. Temper-embrittlement is the reduction in fracture toughness due to a metallurgical change that can occur in some low-alloy steels as a result of prolonged exposure in the temperature range of about 650 °F to 1070 °F (345 °C to 575 °C). This change causes an upward shift in the ductile-to-brittle transition. Although the loss of toughness is not evident at operating temperature, equipment afflicted by temper embrittlement becomes susceptible to brittle fracture during start-up and shutdown processes. This paper includes a literature review and describes the variability in fracture toughness of 2.25Cr 1Mo steel plate material as a function of temperature. Additionally, it presents a case history where high variability was reported in weld deposits. Factors affecting fracture toughness and tempering embrittlement are analyzed and recommendations to maximize fracture toughness and reduce temper embrittlement susceptibility are included. Finally, the paper touches upon technology limitations as dictated by contemporary manufacturing practices. The characterization process incorporates optical microscopy, scanning electron microscopy, hardness, chemistry, impact testing and crack tip opening displacement measurements.
Enhancing Sprint Performance and Biomechanics in Semiprofessional Football Players Through Repeated-Sprint Training
Authors: Romero Valentin , Castaño-Zambudio Adrián , Ortega-Becerra Manuel Alejandro , Vázquez-Diz Juan Antonio , Adalid-Leiva Juan Jesús , Jiménez-Reyes Pedro
Published: November 2024

Repeated-sprint ability is a significant factor in football performance. Notably, hamstring injuries in football players often occur during sprinting activities and fatigue-inducing conditions. Therefore, the aim of this study was to examine the impact of repeated-sprint training (RST) on repeated-sprint ability variables and sprint kinematics. Fourteen semiprofessional men’s soccer players performed 8 weeks of RST, consisting of 1 to 2 sets of 5 to 8 × 30 m repeated sprints separated by 20 to 30 seconds of recovery. Sprint performance was computed from running speed data, and a high-frequency camera (240 Hz) was used to study kinematic data. Paired samples t test and repeated-measures analysis of variance were conducted for each performance and kinematic variable, respectively. After the RST period, moderate to large improvements were observed for 0 to 20 m time, 0 to 30 m time, and 20 to 30 m time. All the repeated-sprint ability-related variables were significantly improved (P < .05). In addition, during fatigue conditions, a decrease in trunk flexion and kick-back mechanism and a reduced overstriding pattern was found after RST. The findings of this study suggest that incorporating RST may lead to improved sprint performance and promote a “safer” sprint pattern, particularly during periods of fatigue.
Decoding the interplay between m
6
A modification and stress granule stability by live-cell imaging
Authors: Li Qianqian , Liu Jian , Guo Liping , Zhang Yi , Chen Yanwei , Liu Huijuan , Cheng Hongyu , Deng Lin , Qiu Juhui , Zhang Ke , Goh Wee Siong Sho , Wang Yingxiao , Peng Qin
Published: November 2024

N
6
-methyladenosine (m
6
A)–modified mRNAs and their cytoplasmic reader YTHDFs are colocalized with stress granules (SGs) under stress conditions, but the interplay between m
6
A modification and SG stability remains unclear. Here, we presented a spatiotemporal m
6
A imaging system (SMIS) that can monitor the m
6
A modification and the translation of mRNAs with high specificity and sensitivity in a single live cell. SMIS showed that m
6
A-modified reporter mRNAs dynamically enriched into SGs under arsenite stress and gradually partitioned into the cytosol as SG disassembled. SMIS revealed that knockdown of YTHDF2 contributed to SG disassembly, resulting in the fast redistribution of mRNAs from SGs and rapid recovery of stalled translation. The mechanism is that YTHDF2 can regulate SG stability through the interaction with G3BP1 in m
6
A-modified RNA-dependent manner. Our results suggest a mechanism for the interplay between m
6
A modification and SG through YTHDF2 regulation.
CO
2
capture, geological storage, and mineralization using biobased biodegradable chelating agents and seawater
Authors: Wang Jiajie , Sekiai Ryota , Tamura Ryota , Watanabe Noriaki
Published: November 2024

Geological storage and mineralization of CO
2
in mafic/ultramafic reservoirs faces challenges including limited effective porosity, permeability, and rock reactivity; difficulties in using seawater for CO
2
capture; and uncontrolled carbonation. This study introduces a CO
2
capture, storage, and mineralization approach with the utilization of biobased biodegradable chelating agents and seawater. An acidic chelating agent solution is used to increase effective porosity and permeability through enhanced mineral dissolution. For instance, applying an acidic
N
,
N
-Bis(carboxymethyl)-
L
-glutamate solution to a porous basalt increased effective porosity by 16% and permeability by 26-fold in 120 hours. Subsequently, alkaline chelating agent–containing seawater improves CO
2
capture and storage by inhibiting mineralization, thus maintaining injectivity while providing ions for mineralization and further expanding storage space. Last, controlled mineralization is achieved by adjusting chelating agent biodegradation. Promising CO
2
storage and mineralization capacities two orders higher than current techniques, this approach reduces required reservoir volume while enhancing efficiency.
Same rule, different genes:
Blimp1
is a pair-rule gene in the milkweed bug
Oncopeltus fasciatus
Authors: Reding Katie , Chung Matthew , Heath Abigail , Hotopp Julie Dunning , Pick Leslie
Published: November 2024

Morphological features of organismal body plans are often highly conserved within large taxa. For example, segmentation is a shared and defining feature of all insects. Screens in
Drosophila
identified genes responsible for the development of body segments, including the “pair-rule” genes (PRGs), which subdivide embryos into double-segment units in a previously unexpected pre-patterning step. Here we show that the milkweed bug
Oncopeltus fasciatus
also uses a pair rule for embryo subdivision but
Oncopeltus
employs different genes for this process. We identified the gene
Blimp1
as an
Oncopeltus
PRG based on its expression pattern, tested its function with RNA interference and CRISPR-Cas9, and generated the first PR mutant in this species. Although it does not have PR function in
Drosophila
, like
Drosophila
PRGs,
Blimp1
encodes a transcription factor required for embryonic viability. Thus, pair-rule subdivision of the insect body plan is more highly conserved than the factors mediating this process, suggesting a developmental constraint on this pre-patterning step.
Description of genome sequences of arthropod-associated spirochetes of the genus
Entomospira
Authors: Sikutova Silvie , Graña-Miraglia Lucía , Vancová Marie , Bílý Tomáš , Sing Andreas , Castillo-Ramirez Santiago , Rudolf Ivo , Margos Gabriele , Fingerle Volker
Published: November 2024

Spirochetal bacteria isolated from arthropods of the genera
Culex
and
Aedes
are termed BR149, BR151 (
Entomospira culicis
), BR193 (
Entomospira entomophila
), and BR208 (
Entomospira nematocerorum
). Genome sizes assembled from Illumina MiSeq and Oxford Nanopore reads varied between 1.67 and 1.78 Mb containing three to six plasmids. GC content ranged from 38.5% to 45.76%.
Supplemental Material: Isochronous Miocene volcaniclastic horizon in the SW Tarim Basin: Composition, ages, origins, and implications for tephrochronology
Authors: Wei Xiaochun , al. et
Published: November 2024

Supplemental Data S1–S9, Figure S1, and Tables S1–S5. 
Movement Recognition and Injury Risk Assessment of Wushu Athletes Based on Computer Vision
Authors: Liu Hongjun , Bai Junya
Published: November 2024

This paper aims to study a method of movement recognition and injury risk assessment for Wushu athletes based on computer vision. Studying the optimization of Wushu athletes’ movement trajectory can effectively improve the athletes’ movement quality. Based on a hybrid real-time synchronization algorithm, the arm motion trajectory model of martial arts athletes is studied. A dynamic and static arm recognition algorithm is proposed, and the motion feature extraction method in Wushu movement is studied. Dynamic arm recognition typically relies on the collection of video or image sequences. These sequences contain the position, shape, and motion trajectory of the arm at different time points. Static arm recognition mainly relies on the acquisition of a single image or image frame. The dynamic arm recognition algorithm captures the motion trajectory and changes of the arm by processing video or image sequences, while the static arm recognition algorithm only processes individual images or image frames. On this basis, the design of the computer software architecture of the digital site system is completed. The real-time collection, analysis, display and storage of motion information and assembly configuration are realized. The simulation results show that the method has high accuracy and provides a powerful scientific basis for improving athletes’ movement injuries. To predict the risk of injury an athlete may suffer during training or competition.
The Impact of Corporate Executives’ Behavior on Company Performance: An Analysis Based on Voice Emotion Classification System and Deep Learning
Authors: Hu Chun , Wu Chuanjian
Published: November 2024

Using deep learning methods, this study provides insights into the significant impact of corporate executive behavior on firm performance, particularly through the lens of vocal emotions. Considering that emotions play a crucial role in leadership effectiveness as well as corporate success, this paper employs a Long Short-Term Memory (LSTM) network to meticulously categorize the emotions in executive speeches into positive, neutral, and negative categories. The initial stage requires rigorous pre-processing of the speech signal, including collection, denoising and feature extraction using Mel Frequency Cepstrum Coefficients (MFCC). Subsequently, LSTM models are trained on these preprocessed data for sentiment classification. This study further innovates by combining sentiment analysis with Key Performance Indicators (KPIs) to scrutinize the correlation between executives’ emotional expressions and company performance. Through statistical analysis and machine learning techniques, we assess the significance of this correlation and present evidence that highlights the predictive power of executives’ emotional expressions on firm performance metrics. Our findings not only contribute to an understanding of the nuanced ways in which leadership behavior impacts firm performance, but also open avenues for enhancing executive training and performance assessment methods. This paper demonstrates the classification accuracy of our model and its effectiveness in correlating executive emotions with firm performance, providing valuable insights into the interplay between leadership emotional intelligence and firm success.
Empirical formula for electron capture half-lives
Authors: Susheela R. S. , Anushree H. S. , Manjunatha H. C. , Sowmya N. , Reddi Rani L. , Vasudha G. S.
Published: November 2024

In this study, efforts were made to propose a semi-empirical equation for electron capture within the atomic number range [Formula: see text] and the mass number range of [Formula: see text]. About 753 nuclei were considered for the same. These nuclei were categorized into four groups based on the parities of both protons and neutrons: even(Z)–even(N), even(Z)–odd(N), odd(Z)–even(N) and odd(Z)–odd(N). Comparative analysis was carried out between the formula’s predictions and experimental data. The improved semi-empirical formula for electron capture belongs to the first category, requiring only the daughter nucleus’s atomic number and decay energy, making them a valuable tool for predicting electron capture half-lives. The present formula effectively describes even-Z-even-N cases. However, significant discrepancies occur when either Z or N is odd in nuclei, indicating that further refinement is necessary to improve.
Regularized FJNW metric in arbitrary dimensions
Authors: Enayatinia Mohammadreza , Mirza Behrouz , Moradzadeh Marzieh , Khuzani Mohammadreza Ebrahimi
Published: November 2024

Interior solution for the Fisher–Janis–Newman–Winicour (FJNW) metric is presented in an arbitrary dimensional space-time. The interior solution matches smoothly to the FJNW metric and therefore represents a globally regularized model of the FJNW solution describing a spherical source of gravitational field in the presence of a massless scalar field. The curvature invariants are derived. It is shown that the energy conditions are valid for a wide range of the metric parameters. We also obtained the Buchdahl limit in various dimensions.
Dynamics over cocycle double cross-products
Authors: Uçgun Fi̇li̇z Çağatay , Esen Oğul , Sütlü Serkan
Published: November 2024

In this paper, we present the Euler–Lagrange and Hamilton’s equations for a system whose configuration space is a unified product Lie group [Formula: see text], for some [Formula: see text]. By reduction, then, we obtain the Euler–Lagrange-type and Hamilton’s-type equations of the same form for the quotient space [Formula: see text], although it is not necessarily a Lie group. We observe, through further reduction, that it is possible to formulate the Euler–Poincaré-type and Lie–Poisson-type equations on the corresponding quotient [Formula: see text] of Lie algebras, which is not a priori a Lie algebra. Moreover, we realize the [Formula: see text]th order iterated tangent group [Formula: see text] of a Lie group [Formula: see text] as an extension of the [Formula: see text]th order tangent group [Formula: see text] of the same type. More precisely, [Formula: see text] is the Lie algebra of [Formula: see text], [Formula: see text] for some [Formula: see text]. We thus obtain the [Formula: see text]th order Euler–Lagrange (and then the [Formula: see text]th order Euler–Poincaré) equations over [Formula: see text] by reduction from those on [Formula: see text]. Finally, we illustrate our results in the realm of the Kepler problem, and the nonlinear tokamak plasma dynamics.
Non-existence of proper η-Einstein Kenmotsu manifolds
Authors: Chaubey Sudhakar Kumar , Suh Young Jin
Published: November 2024

In 1972, Kenmotsu [A class of almost contact Riemannian manifolds, Tohoku Math. J. (2) 24 (1972) 93–103] defined the notion of Kenmotsu manifolds. He has also studied the properties of proper [Formula: see text]-Einstein Kenmotsu manifolds, and proved some basic interesting results. These results have been used by a plenty of authors in establishing their main results on Kenmotsu manifolds. Naturally, the question of existence of proper [Formula: see text]-Einstein Kenmotsu manifold is a prime question in the study of contact geometry. The main goal of this paper is to discuss the existence of proper [Formula: see text]-Einstein Kenmotsu manifolds and to refine some of Kenmotsu’s results. The results of this paper may be used as an erratum of many published papers on Kenmotsu manifolds. In this sequence, we also address the existence of conharmonically flat Kenmotsu manifolds, conformal Ricci flow and almost Ricci solitons on Kenmotsu manifolds.
Roth-type theorem for nonlinear equations in Piatetski-Shapiro primes
Authors: Ren Xiumin , Sun Yu-Chen , Zhang Qingqing , Zhang Rui
Published: November 2024

We consider the nonlinear diophantine equation [Formula: see text] with [Formula: see text] being non-zero and satisfying [Formula: see text]. We show that for [Formula: see text] and [Formula: see text], if the equation has only [Formula: see text]-trivial solutions in a subset [Formula: see text] of Piatetski-Shapiro primes up to [Formula: see text] corresponding to [Formula: see text], then [Formula: see text] [Formula: see text].
Power moments and zero density estimates of automorphic L-function
Authors: Zhang Rui , Zhai Wenguang , Zhang Deyu
Published: November 2024

Let [Formula: see text] be a normalized Maass cusp form for [Formula: see text]. For [Formula: see text], we define [Formula: see text] as the infimum of all numbers [Formula: see text] [Formula: see text] such that [Formula: see text] for any [Formula: see text], where [Formula: see text] is the automorphic [Formula: see text]-function attached to [Formula: see text]. In this paper, we shall establish the upper bounds of [Formula: see text] and obtain the zero density estimates for [Formula: see text] as its applications.
Some cases of the unramified Fontaine–Mazur conjecture
Authors: Luo Yufan
Published: November 2024

We prove some new cases of the unramified Fontaine–Mazur conjecture for [Formula: see text]-adic Galois representations.
Unraveling the Pleiotropic Role of High‐Density Lipoproteins (HDLs) in Autoimmune Rheumatic Diseases
Authors: Giacaglia Marcia B. , Pires Vitória , Santana Monique F. M. , Passarelli Marisa
Published: November 2024

Autoimmune rheumatic diseases (ARDs) exhibit an elevated incidence of cardiovascular disease (CVD). The elevation of inflammatory and immune stress accompanying ARDs contributes to atherosclerosis development and alterations in lipid metabolism and lipoprotein profile add to cardiovascular (CV) risk. The plasma concentration of high‐density lipoprotein cholesterol (HDLc) is inversely related to CVD and serves as a discriminator of CV risk. However, this association is not unequivocal, and changes in HDL functionality appear to emerge as a better indicator of CV risk, albeit difficult to measure and monitor clinically. The modulation of HDLc itself can bring benefits in controlling autoimmunity and reducing ARD activity. Understanding HDL function and each peculiarity involved in ARDs enables to seek means to prevent ischemic outcomes associated with CVD, in the face of the residual CV risk persisting even with controlled disease activity and classic risk factors. By comprehending HDL’s structural and functional nuances, it will be possible to develop more effective strategies to manage the evolution and outcomes of ARDs. It is also necessary to standardize diagnostic methods and establish different markers for each specific disease allowing the design of intervention strategies to restore HDL functionality, reduce residual CV, and prevent, alleviate, or even suppress ARD activity.
Electronic Structures and Magnetic Properties of Zigzag VS2 Single‐Layer Nanoribbons
Authors: Deng Hongyu , Fu Guangming , Shan Dongyong , Chen Wei , Zhang Jianming
Published: November 2024

Inspired by the fabrication of zigzag MoSe2 nanoribbons and MoS2 nanoribbons with well‐defined atomically precise edges, we study the stability, electronic structures, and magnetic properties of zigzag VS2 nanoribbons (ZNRs) with different edge structures and widths. The calculated edge energies for all studied VS2 nanoribbons are less than 0.9 eV/Å, lower than that of fabricated armchair and zigzag graphene nanoribbons, indicating the easy formation of ZNRs. The results show N‐ZNRs terminated with S and V atoms (N‐SV‐ZNRs) is a ferrimagnetic metal. The magnetic moments are mainly contributed by d orbitals of V atoms, and the V2 atom exhibits a spin that is antiparallel to the other V atoms due to the increase of through–space interaction. With hydrogen passivation, the magnetic moment of V2 atom in N‐SV‐ZNRs couples ferromagnetically with other V atoms and N‐SV‐ZNRs becomes half metallic. The N‐ZNRs terminated with V atom (N‐VV‐ZNRs) is found to be a magnetic metal, and the magnetic moments of V atoms around edges are very sensitive to ribbon width. Furthermore, N‐ZNRs with S atom terminations (N‐SS‐ZNRs) is a ferromagnetic quasi‐semiconductor. Only select bands intersect with the Fermi level near the Γ point, and the magnetic moments of all V atoms couple ferromagnetically. These findings are essential for applications of VS2 nanoribbons–based low‐dimensional spintronic devices.
Lymphangitic Carcinomatosis Presenting as Cough: A Case of Occult Metastatic Prostate Adenocarcinoma
Authors: Kumar Sharanya , Seylani Allen , Tuli Rahul , Abedi Eric , Khandelwal Keerti
Published: November 2024

Background: Lymphangitic carcinomatosis (LC), a hallmark of advanced metastatic cancer with a poor prognosis, primarily impacts the lymphatic system of the lungs, manifesting as progressive breathlessness, cough, or hemoptysis. While prostate cancer commonly metastasizes to bones and regional lymph nodes, lung involvement is rare. This case features a patient in generally good health who presented with an insidious dry cough, leading to a diagnosis of Stage 4 prostatic adenocarcinoma with rare lymphangitic spread to the lungs.

Case Presentation: A 70‐year‐old male in good health presented with chest tightness, a dry cough, and sudden left testicular swelling. Imaging revealed interstitial lung markings, severe left hydronephrosis, and prostatomegaly. A prostate biopsy confirmed adenocarcinoma. A PET‐CT scan raised significant concern for LC, prompting the initiation of urgent inpatient chemotherapy with docetaxel.

Conclusion: LC is a metastatic pattern commonly associated with solid tumors, particularly breast, gastric, and lung cancers. Its occurrence in prostate cancer is exceptionally rare. This condition is typically linked with advanced disease and a poor prognosis, often serving as a critical indicator of an underlying malignancy that may otherwise go undetected.