bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure and Mechanical Behavior of Resistance Spot Welded Joints in Advanced High-Strength Q&amp;P 980 Steel
Authors: Nasiri Mahsa , Seyed-Salehi Majid , Ranjbarnodeh Eslam 
Published: February 2024

Abstract
The third generation of advanced high-strength steel has garnered significant interest from both industries and researchers due to the remarkable combination of high strength and ductility. In this study, the relationships between welding parameters, microstructure evolutions, mechanical properties, and failure modes of resistance spot-welded (RSW) joints of Q&P 980 steel sheets were investigated. The microstructure of the alloy, composed of a ferritic matrix with embedded martensite and retained austenite, is analyzed using optical and field emission scanning electron microscopes. The welding process for Q&P steel sheets was examined under different welding currents and durations. Geometric measurements indicate that higher welding current and duration lead to larger weld nuggets, wider HAZ, and greater indentation depth. Tensile-shear tests were conducted to evaluate the mechanical integrity of the welded joints. These tests elucidate different failure modes, predominantly full interfacial failure, but also partial interface failure and peripheral failure in medium welding currents. The results emphasize the importance of nugget size in determining joint strength, with larger nuggets correlating with higher ultimate shear loads. The FESEM analysis of fracture surfaces highlighted the fracture modes, such as shear-dominated plastic deformation and ductile fracture in joints welded at high welding current. The pre-existing central defects and interfacial notches contribute to interfacial failure. Fracture surface analysis of welding samples confirms ductile fracture in peripheral and interfacial regions.
Changing patterns of inequality in a global sample of cities
Authors: Ramos Frederico Roman , Uitermark Justus 
Published: February 2024

Abstract

Urban inequality is widely debated but a lack of data makes it challenging to examine developments over time and across cities. In this contribution, we examine trends in inequality from the 1980s onwards in a sample of 86 cities in Africa, Latin America, and Asia. We track trends in three domains: the labor market, education, and assets (including private goods and public amenities). With descriptive statistics, data visualization, and logistic regression analysis, we show that while inequality in educational attainment is decreasing across all cities in our sample, patterns in the other two domains are more complex. Even though the middle occupational groups is growing in the majority of cities in our sample, there are important exceptions and substantial regional variations. While we find that inequality in terms of assets more often decreased than increased, class position continues to predict access to private goods and public amenities. Although the observed patterns are complex, we find no proof of escalating inequalities in the three domains under study.
A Classification Approach of Conglomerate Reservoirs Considering the Effects of Reservoir Simulation: A Case Study in Triassic Baikouquan Formation, North Slope of Mahu Depression
Authors: Li Xiangyang , Ji Hancheng , Li Fengxia , Wang Haibo , Chen Liang , Huang Zhiwen , Zhang Zhonghao , Shi Xukai 
Published: February 2024

Abstract

The 1Gt oil field's finding has solidified the Mahu oil Field's status, the largest conglomerate oil region in the world, and demonstrated the enormous exploration potential of conglomerate reservoirs. Optimizing and selecting the target interval during hydraulic fracturing is challenging due to the significant heterogeneity of the conglomerate reservoir. Based on issues encountered in the actual production of oil and gas from conglomerate reservoirs of the Baikouquan Formation (T1b), north slope of Mahu Depression, the composition of gravel was examined and analyzed in this paper. A novel classification approach is developed considering the structural and compositional features of the conglomerate reservoir in the T1b. Taking into account the grain size, supporting forms, cementation degree, and compositional properties, the conglomerate of the T1b is categorized into two groups and eight subcategories based on the core and test results. The conglomerates of T1b were initially divided into fan delta front and plain conglomerates according to the type of genesis. Fan delta front conglomerates were divided into four types: tuff, metamorphic rocks and magmatic rocks-dominated gravel-supported cobble-to-boulder lithofacies (A-1); tuff and magmatic rocks-dominated matrix-supported pebble-to-cobble lithofacies (A-2); tuff-dominated matrix-supported granule-to-pebble lithofacies (A-3); and tuff-dominated gravel-supported granule-to-pebble lithofacies (A-4). Fan delta plain conglomerates were divided into four types: tuff and magmatic rocks-dominated gravel-supported granule-to-pebble lithofacies (B-1); tuff and sedimentary rocks-dominated gravel-supported pebble-to-cobble lithofacies (B-2); tuff-dominated gravel-supported cobble-to-boulder lithofacies (B-3); tuff, magmatic rocks and sedimentary rocks-dominated matrix-supported pebble-to-cobble lithofacies (B-4). The sedimentary structure, bedding, lithofacies association, composition, grain size, and poroperm characteristics of the different conglomerate lithofacies are investigated. The favorable lithofacies types have been evaluated from both the geological and engineering perspectives. The insight of this paper is expected to provide some references for oil and gas exploration and development, as well as the selection of favorable lithofacies for hydraulic fracturing of conglomerate reservoirs.
Regulation of soil-plant nitrogen dynamics by (in)organic nitrogen sources with and without biostimulant for sustainable maize (Zea mays L.) production in nitrogen-deficient soil
Authors: Bibi Hamida , Rahim Hafeez , Shams Dilawar Farhan , Nawaz Muhammad , Iqbal Mudassar , Azeem Imran , Baig Shams Ali 
Published: February 2024

Abstract

Nitrogen deficiency is a primary factor contributing to reduced crop production in arid and semiarid regions. Addressing this issue requires optimizing soil-plant nitrogen dynamics. In this field experiment, we investigated the impact of organic (farmyard manure) and inorganic (urea) nitrogen sources, both with and without biostimulant (Bioaab), on soil-plant nitrogen dynamics and sustainable maize (Zea mays L.) production in nitrogen-deficient soil. Five different combinations of farmyard manure (FYM) and urea—0:100, 25:75, 50:50, 75:25, and 100:0—were developed and applied with and without Bioaab in a randomized complete block design with a factorial arrangement in triplicate. Organic (FYM) and inorganic (urea) nitrogen sources, whether combined with Bioaab or not, significantly (p < 0.05) improved soil-plant nitrogen content and maize yield. The addition of FYM, whether Bioaab was present or not, had no significant (p > 0.05) impact on yield parameters. In contrast, the application of Bioaab enhanced soil-plant nitrogen dynamics, as indicated by increased plant total nitrogen (1.37%) and total nitrogen uptake (95.7 kg ha− 1) by maize plants, resulting in significantly higher yield compared to non-Bioaab treated plots. However, non-Bioaab treated pots surprisingly recorded maximum soil total nitrogen content (0.057%). Moreover, the plot treated with Bioaab recorded the maximum biomass production (7.99 tons ha− 1), number of grains (2.873 tons ha− 1), and soil organic matter content (1.20%). In conclusion, the use of inorganic fertilizer with a biostimulant (Bioaab) is crucial for improving crop yield and nitrogen release.
High-Pressure Ultrafast Time-Resolved Far-Infrared Full-spectrum Spectroscopy with Air-Based Upconversion
Authors: Yang Yanqiang , Zhu Gangbei , Zeng Yangyang , Mu Jian , Zheng Zhaoyang , Yu Guoyang 
Published: February 2024

Abstract
Most condensed materials exhibit characteristic excitations in the far-infrared range. The ultrafast dynamics of these excitations significantly influence the fundamental physical and chemical properties of the materials. Moreover, modulating the dynamics of these excitations through pressure variations is intriguing for unveiling the key microphysical processes involved and can offer dynamic experimental support for exploring novel materials. In this study, we demonstrate the first experimental elucidation and application of ultrafast time-resolved far-infrared full-spectrum spectroscopy combined with high-pressure diamond anvil cell (DAC) technology. The combination of an air-plasmon-based continuum and an air-based single-shot upconversion detection technique have been first employed in high-pressure time-resolved infrared spectroscopy. The air-plasmon-based ultrabroadband far-infrared continuum was directed into a DAC and the transmitted pulse was detected in a single shot form through four-wave mixing in the air to avoid the absorptions from phonon modes of the nonlinear medium. It allows the real-time capture of the spectrum spanning from < 50 to > 1800 cm− 1, with a few-cm− 1 spectral resolution. We investigate the pressure-dependent vibrational coupling dynamics of the complete set of vibrational fingerprint modes in microcrystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) following mode-selective vibrational mode excitation. The results reveal that pressure enhances the vibrational coupling and energy transfer between the excited vibrational modes and doorway modes. The combination of high-pressure technology and time-resolved full-spectrum infrared spectroscopy opens up new perspectives for the study of the ultrafast phenomena in material science.
Role of Small Bowel Capsule Endoscopy in Determining the Treatment Strategy for Duodenal Follicular Lymphoma: A Single-Center Retrospective Study
Authors: Kang Donghoon , Min Gi-June , Kim Tong Yoon , Jeon Young-Woo , Cho Yukyung , Park Jae Myung , O Joo Hyun , Choi Byung-Ock , Park Gyeongsin , Cho Seok-Goo 
Published: February 2024

Abstract

In this single-center retrospective study, we aimed to verify the extent of duodenal follicular lymphoma (DFL) and investigate the role and clinical significance of video capsule endoscopy (VCE) in this process. We analyzed the clinical and imaging data of 40 patients diagnosed with DFL. Imaging workup and bone marrow biopsies revealed DFL only in the gastrointestinal tract (stage I) in 22 patients and in local lymph nodes (stage II1), distant lymph nodes (stage II2), pancreas (stage II2Epancreas), and extranodal regions (stage IV) in 1, 3, 1, and 13 patients, respectively. Fifteen of the 23 patients with localized (stages I and II1) DFL underwent VCE for comprehensive small bowel evaluation, which revealed lesion extension beyond the duodenum in 10 patients (66.7%). A watch-and-wait strategy was implemented for 1 patient and systemic chemotherapy was administered to the remaining nine. Of the eight patients without VCE, seven and one received radiotherapy and observation, respectively. Nine of the 23 patients (39.1%) received systemic treatment based on positive VCE results. Only one of the 17 patients with advanced-stage DFL (stages II2 and IV) accepted radiotherapy; 16 underwent systemic chemotherapy. During follow-up (median, 48.4 months), two relapse events occurred in the advanced stage, with no lymphoma-associated deaths. DFL tends to be indolent with favorable outcomes. Proactive VCE for diagnosing DFL is recommended to determine small bowel involvement, which may influence subsequent treatment decisions.
Effect of waste fly ash incorporated into the polymer matrix and surface interactions on radiation shielding effectiveness
Authors: Özcan Mücahid 
Published: February 2024

Abstract
This study focuses on enhancing the surface modification of waste fly ash, which is generated by coal combustion in thermal power plants. The electrospinning method was used to reinforce waste fly ash onto PAN nanofiber. The present study investigates the surface interaction between ceramic fly ash particles and PAN polymer and the potential synergy that may arise from their combination. The flexing capacity of PAN fiber has been found to reach up to three times its original size while simultaneously integrating the fly ash ceramic component into its structural composition. It has been discovered that adding fly ash to PAN Fiber improves its gamma and neutron shielding properties. According to this understanding, the radiation at 0.05 MeV energy can be reduced by 50% with just 0.7 cm of fly ash-reinforced PAN nanofiber material.
EvoAI enables extreme compression and reconstruction of the protein sequence space
Authors: Zhang Shuyi , Ma Ziyuan , Li Wenjie , Shen Yunhao , Xu Yunxin , Liu Gengjiang , Chang Jiamin , Li Zeju , Qin Hong , Tian Boxue , Gong Haipeng , Liu David , Thuronyi B , Voigt Christopher 
Published: February 2024

Abstract

Designing proteins with improved functions requires a deep understanding of how sequence and function are related, a vast space that is hard to explore. The ability to efficiently compress this space by identifying functionally important features is extremely valuable. Here, we first establish a method called EvoScan to comprehensively segment and scan the high-fitness sequence space to obtain anchor points that capture its essential features, especially in high dimensions. Our approach is compatible with any biomolecular function that can be coupled to a transcriptional output. We then develop deep learning and large language models to accurately reconstruct the space from these anchors, allowing computational prediction of novel, highly fit sequences without prior homology-derived or structural information. We apply this hybrid experimental-computational method, which we call EvoAI, to a repressor protein and find that only 82 anchors are sufficient to compress the high-fitness sequence space with a compression ratio of 1048. The extreme compressibility of the space informs both applied biomolecular design and understanding of natural evolution.
Poly(2-vinylpyridine) magnetite nanoparticles for 5-fluorouracil targeted delivery: synthesis, uptake and release study
Authors: Korolkov I. V. , Izbasar K. A. , Bekbol Zh. A. , Zibert A. V. , Shumskaya A. E. , Lissovskaya L. I. , Korganbayeva L.N. , Zdorovets M. V. 
Published: February 2024

Abstract
One of the major limitations of anti-cancer drug is their poor selectivity and high toxicity. Present study is aimed overcoming these difficulties by development targeted drug delivery systems. Drug delivery systems were synthesized based on magnetite nanoparticles with grafted poly(2-vinylpyridine) from their pre-modified surface with 3-(trimethoxysilyl)propyl methacrylate. Physical and chemical properties of synthesized samples were examined by FTIR, XRD, VSM, EDA, Mössbauer spectroscopy. 5-FU release from nanocarriers was estimated using UV-Vis spectroscopy.
An evaluation of the effectiveness of an updated pre-service midwifery curriculum integrated with emergency obstetrics and newborn care in Kenya: a cluster randomised controlled trial
Authors: Shikuku Duncan N , Mwaura Catherine , Nandikove Peter , Uyara Alphonce , Allott Helen , Waweru Lucy , Nyaga Lucy , Tallam Edna , Bashir Issak , Ndirangu Eunice , Bedwell Carol , Bar-Zeev Sarah , Ameh Charles 
Published: February 2024

Abstract

Introduction
Quality midwifery education is central to improving midwifery service delivery and maternal and newborn health outcomes. In many settings, midwifery educators insufficiently prepared for their teaching role and deficient curriculum compared to international standards affect the quality of midwifery graduates. This study assessed the effectiveness of an EmONC enhanced midwifery curriculum delivered by trained and mentored midwifery educators on the quality of education and student performance in Kenya.
Methods
A cluster randomised controlled trial (ISRCTN 14203188) in 20 midwifery colleges (12 intervention and 8 control colleges). Educators in both arms received training in teaching/EmONC skills to deliver the updated national midwifery curriculum, with those in the intervention arm receiving additional mentoring every three months after training for 12 months. Educators’ knowledge and confidence in EmONC/teaching skills was assessed before and after training and at 3, 6, 9 and 12 months. Teaching skills observations at baseline and endline in both study arms were also assessed using a checklist. Knowledge, confidence and three selected EmONC practical skills among final year midwifery students were assessed. Linear mixed effects models were used to evaluate the effect of intervention on educators and students.
Results
The intervention arm had 45 educators and 91 students while the control arm had 29 educators and 55 students in the study. Immediately after training educators’ knowledge improved (61.3–73.3%, p < 0.001) and confidence to teach EmONC (3.1 to 4.2 out of 5, p < 0.001) improved. No evidence of a difference in either knowledge or confidence was detected for period or study arm (p > 0.05). The observed teaching skill scores of educators in the intervention arm were significantly higher compared with those of controls at endline (mean difference, 16.5; 95%CI, 3.2–29.8, p = 0.02). Scores for students in the intervention arm were significantly higher than those in controls for knowledge (mean difference, 8.3 [1.6–15.0]) and the three skills assessed (mean difference (95%CI): 22.4 (10.8–33.9) for shoulder dystocia, 17.9 (2.0-33.9) for newborn resuscitation and 17.0 (8.0–26.0) for maternal resuscitation. Shortage of faculty and inadequate support in clinical placement were major challenges for quality midwifery education.
Conclusion
Knowledge and confidence of educators in teaching EmONC was improved immediately after training. Mentoring was effective in improving the quality of educators’ EmONC teaching skills. Students in intervention arm had higher performance in EmONC knowledge and skills. Institutional investments are needed for quality delivery of an EmONC-enhanced curriculum.
Effects of woodland slope on heavy metal migration via surface runoff, interflow, and sediments and associated potential ecological risks following the application of sewage sludge
Authors: Xian Lihua , Lu Dehao , Yang Yuantong , Feng Jiayi , Fang Jianbo , Jacobs Douglass F. , Wu Daoming , Zeng Shucai 
Published: February 2024

Abstract

The application of sewage sludge (SS) to woodland is an effective approach for the disposal and utilization of SS. However, the woodland slope may determine the risk of heavy metal (HM) migration via runoff. We conducted indoor rainfall simulations and natural rainfall experiments to clarify the effect of slope on the migration of HMs via runoff (including surface and interflow) and sediments. In the simulated rainfall experiment, HMs lost via sediments increased by 9.79–27.28% when the slope increased from 5° to 25°. However, in the natural rainfall experiment, when the slope of forested land increased from 7° to 23°, HMs lost via surface runoff increased by 2.38% to 6.13%. It revealed that the surface runoff water on a high slope (25°) posed high water quality pollution risks. The migration of HMs via surface runoff water or interflow increased as the steepness of the slope increased. The total migration of Cu, Zn, Pb, Ni, Cr and Cd via sediment greatly exceeded that via surface runoff and interflow. Particles ≤0.05 mm contributed the most to the ecological risks posed by sediments. Cd was the main source of potential ecological risks in sediments under both experimental conditions.
Research on the aggregation phenomena in moraine soil: a new approach to disperse them through a particle size analysis
Authors: Lu Tuo , Tie Yongbo , Tang Yaming , Ning Zhijie , Gong Lingfeng 
Published: February 2024

Abstract

Moraine soils exposed to the moraine landscape surface due to glaciers retreating and global warming have been the subject of interest for researchers. The particle size distribution (PSD) of moraine soils is essential to understanding their engineering properties and soil characteristics. However, the wide aggregation phenomena observed in these soils introduce difficulties in particle size analysis. To overcome this, an experimental group test (EGT) and control groups test (CGT) were designed, which included a series of pretreatment methods to disperse particles, such as grain sieving test, laser diffraction test, microscopic observation, and scanning electron microscope. The tests were performed to record the aggregation phenomena and perform particle size test analysis. The results revealed widespread evidence of aggregation phenomena in each grain group (ranging from < 0.075 mm to 60 mm ~ 40 mm), encapsulated by three basic conceptual models (Core-coating, Core(s)-coat, and Coat-coring) for moraine soil. A new pretreatment method was developed, which involved the addition of 0.5% polycarboxylate in optimal ultrasonic dispersion to disperse aggregation phenomena before the sieving and laser diffraction tests. This method proved to be effective in removing the aggregation phenomena, which significantly impacted on the particle size distribution of moraine soils. The aggregation phenomena caused an overestimation of the content of the gravel group (about 7.91%) and an underestimation of the content of the silt-clay group (about 5.07%). After effectively removing the aggregation phenomena, many samples collected from poorly graded gravelly soils (GP) became silty sand soil (SM) and silty gravel soil (GM). Additionally, the average particle size was reduced by approximately 40%.
Computational Analysis of Bulb-Shape Ribs Roughened Absorber Plate of Solar Air Heater
Authors: Mor Swati , Sikarwar Basant Singh , Kumar Niraj , Gautam sachin Singh 
Published: February 2024

Abstract
In this work, thermo-hydrodynamic simulation was carried out for bulb-shaped ribs roughened absorbing surface of solar air heater at 1kW/m2 for and various Reynolds numbers. Primarily, sensitivity analysis of turbulent models was carried for flow over the surface, and it observed that RNG k-\(\epsilon\) model results is more closed with respect to Dittus-Boelter equation. After selection of appropriate turbulence model, simulations were carried out on a bulb-shape rib and other shapes of roughened ribs surface. This study reveals that absorber bulb shaped ribs roughened surface has at least two times more performance improvement factor (Nu/f) as compared to the other ribbed shape roughened surface. Eventually, the Nusselt number and Coefficient friction for bulb shaped ribs roughened surface were correlated in terms of Reynolds number (Re) and relative roughness (β). These correlations are substantial for designing solar air heating systems for bulb-shaped ribs roughened as absorbing surface.