bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac Damage and Conduction Disorders after Transcatheter Aortic Valve Implantation
Authors: Damas François , Nguyen Trung Mai-Linh , Postolache Adriana , Petitjean Hélène , Lempereur Mathieu , Viva Tommaso , Oury Cécile , Dulgheru Raluca , Lancellotti Patrizio
Published: January 2024

Recently, a staging system using 4 grades has been proposed to quantify the extent of cardiac damage associated with aortic stenosis (AS), namely AS-related cardiac damage staging (ASCDS). ASCDS is independently associated with all-cause mortality and important clinical outcomes. To evaluate whether it might be associated with the occurrence of conduction system disorders after TAVI, a total of 119 symptomatic patients with severe AS who underwent a TAVI were categorized according to ASCDS: group 1 (13.5%): no or LV damage; group 2 (58.8%): left atrial/mitral valve damage, atrial fibrillation (AF); group 3 (27.7%): low-flow state, pulmonary vasculature/tricuspid valve/RV damage. After TAVI, 34% of patients exhibited LBBB and 10% high-degree atrioventricular block (HD-AVB). No patient in group 1 developed HD-AVB whereas new LBBB was frequent in groups 2 and 3. Twenty-one patients presented with paroxysmal AF with a higher rate for each group increment (group 1: n = 0, 0%; group 2: n = 11, 15.7%; group 3: n = 10, 30.3%) (p = 0.012). Patients in group 3 had the higher rate of permanent pacemaker implantation (PPMI) (group 1: n = 1, 6.3%; group 2: n = 7, 10%; group 3: n = 9, 27.3%) (p = 0.012). In conclusion, ASCDS might help identify patients at higher risk of conduction disorders and PPMI requirement after TAVI.
Women with Endometriosis—Who Is at Risk for Complications Associated with Pregnancy and Childbirth? A Retrospective Case–Control Study
Authors: Gruber Teresa Mira , Ortlieb Laura , Henrich Wolfgang , Mechsner Sylvia
Published: January 2024

Women with endometriosis (EM), particularly the manifestations of adenomyosis (AM) and deep infiltrating endometriosis (DIE), suffer from pain and sterility. DIE also appears with several specific obstetric complications. To determine the risk profile, we designed a retrospective case–control study. Primary outcomes were defined as the risk of preterm birth and caesarean delivery (CD). Primiparous singleton pregnancies in women with DIE were compared with controls without EM. We matched for mode of conception and maternal age. A total of 41 women diagnosed with DIE and 164 controls were recruited. A total of 92.7% of the cases were also diagnosed with AM. Preterm birth occurred in 12.2% of cases and in 6.7% of controls. The difference was not statistically significant (OR: 1.932; 95% CI: 0.632–5.907). The rate of CD was similar in both groups. Remarkably, placental implantation disorders in the form of placenta praevia were eight times more frequent in women with DIE (9.8%) than in controls (1.2%, OR: 8.757; 95% CI: 1.545–49.614). Neonatal outcome was similar in both groups. Four out of fourteen cases reported abdominal wall endometriosis after CD. Women with DIE/AM and with placenta praevia are at risk of bleeding complications. After CD, they can develop abdominal wall EM. We therefore suggest evaluating the birth mode in each woman with DIE/AM.
Thyroid Disorders in Systemic Sclerosis: A Comprehensive Review
Authors: Cherim Aifer , Petca Răzvan-Cosmin , Dumitrascu Mihai-Cristian , Petca Aida , Candrea Elisabeta , Sandru Florica
Published: January 2024

Systemic sclerosis, also referred to as scleroderma, is a chronic autoimmune disease that affects both internal organs and the skin. Systemic sclerosis predominantly affects female patients and can coexist with other disorders, including those affecting the thyroid gland. Common symptoms such as fatigue and weight changes can be attributed to either systemic sclerosis or thyroid disease. In this comprehensive review, an extensive analysis is conducted using research from 2002 to 2022, sourced from PubMed. The main focus of this exploration is to understand the intricate relationship between thyroid disorders and systemic sclerosis. We obtained these results by analyzing a number of 32285 patients included in 21 original studies. The existing evidence suggests that there is a higher incidence of elevated TSH levels and hypothyroidism in patients with systemic sclerosis, particularly in females, compared to the general population. This remains true even when comparing patients from iodine-deficient regions. Additionally, there is an increased occurrence of hyperthyroidism in the context of systemic sclerosis, which negatively impacts the prognosis of these patients. Furthermore, thyroid antibodies, predominantly anti-thyroid peroxidase (anti-TPO) antibodies, and autoimmune disorders are more commonly observed in individuals with systemic sclerosis. Although thyroid nodules are not specifically linked to the disease, when considering thyroid volume, it is observed that the thyroid gland in systemic sclerosis patients has a decreased volume, possibly due to fibrosis. Conversely, other studies have revealed that patients without autoimmune thyroid diseases (AITDs) are more likely to have a history of digital ulcers, pulmonary fibrosis detected by computed tomography scan, and a requirement for immunosuppressive medication. The majority of the studies did not establish a connection between thyroid disease in these patients and the occurrence of the limited or diffuse forms of systemic sclerosis, as well as the presence of digital ulcers, calcinosis, pulmonary arterial hypertension, scleroderma renal crisis, Raynaud phenomenon, and various other clinical manifestations.
Perioperative Exercise Testing in Pregnant and Non-Pregnant Women of Reproductive Age: A Systematic Review
Authors: Spicer Madeleine G. , Dennis Alicia T.
Published: January 2024

Background: Women have classically been excluded from the development of normal data and reference ranges, with pregnant women experiencing further neglect. The incidence of Caesarean section in pregnant women, and of general operative management in young women (both pregnant and non-pregnant), necessitates the formal development of healthy baseline data in these cohorts to optimise their perioperative management. This systematic review assesses the representation of young women in existing reference ranges for several functional exercise tests in common use to facilitate functional assessment in this cohort. Methods: Existing reference range data for the exercise tests the Six Minute Walk Test (6MWT), the Incremental Shuttle Walk Test (ISWT) and Cardiopulmonary Exercise Testing (CPET) in young women of reproductive age were assessed using the MEDLINE (Ovid) database, last searched December 2023. Results were comparatively tabulated but not statistically analysed given underlying variances in data. Results: The role of exercise testing in the perioperative period as an assessment tool, as well as its safety during pregnancy, was evaluated using 65 studies which met inclusion criteria. Conclusion: There is a significant lack of baseline data regarding these tests in this population, especially amongst the pregnant cohort, which limits the application of exercise testing clinically.
Role of Lifestyle in Thoracic Outlet Syndrome: A Narrative Review
Authors: Abraham Pierre , Lecoq Simon , Mechenin Muriel , Deveze Eva , Hersant Jeanne , Henni Samir
Published: January 2024

Introduction: The presence of a positional compression of the neurovascular bundle in the outlet between the thorax and the upper limb during arm movements (mainly abduction) is common but remains asymptomatic in most adults. Nevertheless, a certain number of subjects with thoracic outlet positional compression will develop incapacitating symptoms or clinical complications as a result of this condition. Symptomatic forms of positional neurovascular bundle compression are referred to as “thoracic outlet syndrome” (TOS). Materials and methods: This paper aims to review the literature and discuss the interactions between aspects of patients’ lifestyles in TOS. The manuscript will be organized to report (1) the historical importance of lifestyle evolution on TOS; (2) the evaluation of lifestyle in the clinical routine of TOS-suspected patients, with a description of both the methods for lifestyle evaluation in the clinical routine and the role of lifestyle in the occurrence and characteristics of TOS; and (3) the influence of lifestyle on the treatment options of TOS, with a description of both the treatment of TOS through lifestyle changes and the influence of lifestyle on the invasive treatment options of TOS. Results: We report that in patients with TOS, lifestyle (1) is closely related to anatomical changes with human evolution; (2) is poorly evaluated by questionnaires and is one of the factors that may induce symptoms; (3) influences the sex ratio in symptomatic athletes and likely explains why so many people with positional compression remain asymptomatic; and (4) can sometimes be modified to improve symptoms and potentially alter the range of interventional treatment options available. Conclusions: Detailed descriptions of the lifestyles of patients with suspected TOS should be carefully analysed and reported.
Development and Characterization of Flax–Gypsum Composites
Authors: Chakarala Vamsi , Schuster Jens , Shaik Yousuf Pasha
Published: January 2024

Flax–gypsum composites are an emerging class of environmentally friendly materials that combine the mechanical properties of gypsum with the advantageous characteristics of flax fibers. The production of flax–gypsum composites involve the incorporation of flax fibers, derived from the flax plant, into gypsum matrix systems. In order to create a uniform distribution of fibers within the gypsum matrix, the hand lay-up approach has been used to produce the specimens. The fiber content and orientation significantly influence the resulting mechanical and physical properties of the composites. Various tests were conducted on the samples, such as a flexural test, a compression test, a density test, a water absorption test, and a microscopy test. The addition of flax fibers imparts several desirable properties to the gypsum matrix. When combined with gypsum, these fibers enhanced the composite’s mechanical properties, such as flexural strength and compressive strength. The results indicated improved compression and flexural strengths due to effective load transfer within the matrix, for up to 10% of fiber loading. A decrease in composite density upon flax fiber addition results in a lighter material, enabling insights for various applications.
CFD Analysis of Microplastic Transport over the Slopes
Authors: Quyen Le Duc , Park Young-Gyu , Lee In-cheol , Choi Jun Myoung
Published: January 2024

Microplastics, ubiquitous in our environment, are significantly impacted by the hydrodynamic conditions around them. This study utilizes CFD to explore how various breaker types influence the dispersion and accumulation of microplastics in nearshore areas. A special focus is given to the impact of wave dynamics and particle size, particularly on buoyant microplastics in spilling breakers. It was discovered that spilling breakers, common on gently sloping seabeds, encourage broad dispersion of microplastics, notably for smaller-sized particles. Plunging breakers exhibit a similar pattern but with less dispersion and an initial forward movement of neutral and heavy particles. Surging breakers feature minimal dispersion and a distinct oscillatory motion. It has been observed that medium-sized particles with a 1 mm diameter in this work exhibit the most substantial forward movement, likely due to an optimal balance between inertia and viscosity, enabling an effective response to wave momentum. Larger particles, influenced mainly by inertia, tend to show less dispersion and advection. Meanwhile, smaller particles, more affected by viscosity, demonstrate greater dispersion, interacting extensively with wave-induced turbulence. This study reveals the significance of inertia in the behavior of microplastics over slopes, emphasizing the importance of considering inertial effects for precise modeling of microplastic movement in nearshore areas.
A Wetting and Drying Approach for a Mode-Nonsplit Discontinuous Galerkin Hydrodynamic Model with Application to Laizhou Bay
Authors: Chen Zereng , Zhang Qinghe , Ran Guoquan , Nie Yang
Published: January 2024

A wetting and drying treatment for a three-dimensional discontinuous Galerkin hydrodynamic model without mode splitting (external and internal modes) was developed. In this approach, computing elements are classified into wet, dry, and semidry elements, which are treated differently. In a Runge–Kutta time step, the reconstruction of the semidry elements and the combined utilization of two- and three-dimensional limiters help the model maintain stability. Numerical results show that the wetting and drying method can achieve a well-balanced property under the condition of still-water equilibrium and can reasonably describe the variation process of wetting and drying regions during a long wave run-up on a uniform slope and a tidal cycle in a basin with a variable slope. Analysis of the role of the limiters in the model indicated that the robustness of the three-dimensional hydrodynamic model can be effectively maintained when the two- and three-dimensional limiters are jointly applied for wetting and drying process simulation. A three-dimensional discontinuous Galerkin hydrodynamic model was applied with the presented wetting and drying method to simulate the tidal current evolution of a spring tidal cycle in southwestern Laizhou Bay in the Bohai Sea, in November 2003, and the simulated results of the water surface elevation and vertical layered current velocities agreed well with the measured data.
Health Policy for Prostate Cancer Early Detection in the European Union and the Impact of Opportunistic Screening: PRAISE-U Consortium
Authors: Beyer Katharina , Leenen Renée , Venderbos Lionne D. F. , Helleman Jozien , Denijs Frederique , Bramer Wichor , Vasilyeva Vera , Briers Erik , Rivas Juan Gomez , Chloupkova Renata , Majek Ondrej , Annemans Lieven , Vynckier Pieter , Basu Partha , Chandran Arunah , van den Bergh Roderick , Collen Sarah , van Poppel Hendrik , Roobol Monique J. ,   on behalf of the PRAISE-U Consortium
Published: January 2024

With the new policy recommendation in 2022 to explore the possibilities of screening for prostate cancer by the European Commission, the landscape for prostate cancer early detection is evolving. In line with this recommendation, the PRAISE-U project aims to evaluate the early detection and diagnosis of prostate cancer through customised and risk-based screening programmes, with the goal to align protocols across European Union member states. This systematic review is part of the PRAISE-U project, with the goal to review the policy, medical guideline recommendations, and the current level of opportunistic screening presented in the scientific literature on prostate cancer early detection from 2016 to 2023 in European Union member states. An extensive literature search was performed on 1 June 2023 in a large number of databases, including Embase.com, Medline (Ovid), Web of Science Core Collection, Google Scholar, and Policy Commons. We identified 318 articles (qualitative, quantitative, and reviews), of which 41 were included in the full-text screening. Seventeen articles were ultimately identified as eligible for inclusion. The included articles revealed significant variations towards PSA-based early detection policies for prostate cancer in nine European countries. Despite official recommendations, opportunistic screening was prevalent across all nine countries regardless of recommendations for or against PSA-based early detection. This systematic review suggests that the current early detection policies are not fit for purpose. High levels of opportunistic screening and overdiagnosis persist, prompting policy recommendations for standardised guidelines, informed decision making, and increased awareness to improve efficiency and effectiveness in early detection.
Assessing the Efficacy of Laser Therapy and Autologous Platelet-Rich Plasma (PRP) Treatment for Chronic Wounds
Authors: Mircea Sandor , Laura Maghiar , Sebastian Horgos Maur , Lucian Borza Ioan , Maria Farcas Dorina , Daniel Ciurescu , Dragos Cheregi Cornel , Loredana Hurjui Liliana , Liliana Sachelarie , Bianca Maghiar Paula
Published: January 2024

(1) Background: The management of persistent wounds is a topic of significant concern, particularly when they become chronic. Clinicians are focused on reducing the healing duration of chronic wounds and employing the most efficient treatments. Successful wound management requires an understanding of standard healing processes, the elements that can impede healing progress, and strategies to manage these impediments. (2) Methods: We participated in a study involving a cohort of 115 patients. Data were collected through subjective assessments via questionnaires, examining the comparative effects of laser therapy and platelet-rich plasma (PRP) on patients’ conditions and monitored the progression of chronic wounds. For the study, we utilized a branded laser equipped with a 12-watt probe to stimulate chronic wounds in 65 patients, while the PRP procedure was administered to 50 patients. (3) Results: We observed a greater improvement in local symptoms among the patients who received laser therapy compared to those in the PRP group. (4) Conclusions: We consider both therapies to be of significant importance due to their positive and beneficial effects, particularly on the symptomatology and progression of chronic wounds. Nevertheless, superior results were documented in patients who underwent laser therapy.
The Effect of Technology Readiness on Adopting Artificial Intelligence in Accounting and Auditing in Vietnam
Authors: Anh Nguyen Thi Mai , Hoa Le Thi Khanh , Thao Lai Phuong , Nhi Duong Anh , Long Nguyen Thanh , Truc Nguyen Thanh , Ngoc Xuan Vu
Published: January 2024

This research article focuses on investigating the impact of technology readiness (TR) on the adoption of artificial intelligence (AD) by accountants and auditors, utilizing intermediary factors, such as perceived usefulness (PU) and perceived ease-of-use (PEOU), within companies in Vietnam. Based on 143 survey responses, the results demonstrate a positive relationship between TR and AI adoption among professionals in the accounting and auditing industry. Additionally, the analysis reveals that the intermediary factors PU and PEOU positively influence AI adoption. TR consistently relates with PU and PEOU in applying artificial intelligence in accounting and auditing. The result of the experiment study is that technology readiness positively impacts the AI adoption of accountants and auditors from companies in Vietnam. Hence, perceived usefulness and ease of use mediate the relationship between technology readiness and the adoption of AI technologies by workers in the accounting and auditing industry. This study contributes not only academically by enriching scientific knowledge on AI adoption but also holds practical significance by suggesting training and development policies from a business perspective in the future.
Can Urbanization-Driven Land-Use and Land-Cover Change Reduce Ecosystem Services? A Case of Coupling Coordination Relationship for Contiguous Poverty Areas in China
Authors: Zhang Jian , Lu Xin , Qin Yao , Zhang Yuxuan , Yang Dewei
Published: January 2024

New urbanization often leads to land-use and land-cover change (LUCC), which inevitably affects ecosystem services (ESs). Although it is traditionally believed that urbanization reduces ecosystem services, some studies have shown that reasonable urban development facilitates ecosystem conservation. Previous studies have focused on the impacts of urbanization on either LUCC or ESs, with fewer dynamic assessments of the coordination of the three. Taking China’s contiguous poor areas (CPAs) as an example, this study applied coupling coordination, path analysis, and a multiscale geographically weighted regression (MGWR) model to identify the dynamic relationship among urbanization, land use, and the environment and then predicted their coupling coordination under shared socioeconomic pathways (SSP-RCP) in 2035 using the Patch Generation Land Use Simulation (PLUS) and a random forest model. The results of the study show that (1) urbanization, land-use change, and environmental loads in China’s CPAs showed an inconsistent upward trend. There was a slight overall decrease in ESs before 2013, which was consistent with the early stage of the Environmental Kuznets Curve (EKC); after that time, they showed different characteristics. (2) From 2000 to 2018, the coupling coordination degree of CPAs decreased slightly due to urbanization, geographic factors, and grassland and unused land. LUCC was essential to maintaining the system balance. The SN (southern contiguous poverty area) was at a basic level of coordination, while the other regions showed a moderate imbalance. (3) According to scenario projections, the degree of coupling coordination in all regions will increase by 2035. Environmental prioritization and sustainable routes are the best options for CPAs’ development. The SN is more stable, while the WN (western contiguous poverty area) has the lowest coupling coordination. (4) Environmentally friendly urbanization should be carried out with land management tailored to local conditions. Measures that could be recommended include establishing ecological pilot zones in SN areas, prioritizing the protection of grassland ecosystems in WN areas, and promoting intensive land use in the NN (northern contiguous poverty area). The present study offers a novel perspective on the interplay between the economy and the environment at the county level and achieves predictive coupling coordination through the integration of PLUS and random forest models. This investigation into coordinated urbanization–LUCC–ES development in CPAs yields valuable insights for enhancing environmental and economic well-being in similar regions within China, as well as globally.
Urban Heat Island and Reduced Habitat Complexity Explain Spider Community Composition by Excluding Large and Heat-Sensitive Species
Authors: Cabon Valentin , Quénol Hervé , Dubreuil Vincent , Ridel Aurélien , Bergerot Benjamin
Published: January 2024

Along with worldwide urbanization, upheavals in habitat and temperature are major threats for biodiversity. However, due to their interdependence, their relative roles as drivers of animal community composition remain entangled. Here, we investigated how taxonomic and functional compositions of arthropod communities were related to uncorrelated habitat and temperature gradients, and compared landscape (i.e., urbanization, Urban Heat Island (UHI)) to local variables (i.e., vegetation height and cover, near-ground temperature). We sampled 20,499 spiders (137 species) on 36 grasslands in Rennes (northwestern France). Unlike rural areas, urban sites were characterized by short vegetation and intense UHI, hosted species-poor communities, and were composed of small thermophilic species. UHI intensification and local loss of habitat complexity (short and dense vegetation) were associated with declining large and heat-sensitive species. These results highlight the prevalent role of urban warming, rather than land cover change, as an urban filter. Further, we show that landscape-scale UHI, not local temperature, filters species according to their functional attributes. UHI can therefore be considered as a thermal barrier, filtering species according to their physiological capacity to cope with urban thermal conditions. Finally, to counterbalance biotic homogenization, we argue for the importance of implementing complex habitat structures at the local scale within urban green infrastructure.
Exploring Defuturing to Design Artificial-Intelligence Artifacts: A Systemic-Design Approach to Tackle Litigiousness in the Brazilian Judiciary
Authors: Münch Luciane Amaral Corrêa , Ferraz Taís Schilling
Published: January 2024

From the perspective of defuturing design philosophy, this article discusses the close relationship between the growing body of artificial-intelligence (AI) artifacts in the Brazilian Judiciary and the phenomenon of litigiousness therein. Litigiousness has traditionally been tackled through mechanisms that increase productivity and efficiency in case processing, a strategy that has not succeeded in reducing litigiousness, as data make evident. Analyzing data from relevant sources, this article demonstrates that AI artifacts mostly perform tasks related to clustering and mass handling of cases, following the same path dependency. Consequently, they entail risks of judges’ alienation and loss of agency, which can negatively impact citizens’ fundamental rights. Moreover, they defuture; that is, they erase other (preferable) futures. Albeit AI artifacts can play a part in tackling litigiousness, there should be a critical reflection upon futuring and defuturing. Therefore, this article recommends that SoDF—a systemic approach to design that seeks to explore design consequences, futuring and defuturing—be mandatory to any AI design process. Additionally, it proposes continuous judicial monitoring for alienation and loss of agency, as well as investments in judicial education to empower judges to effectively control and supervise AI artifacts. Finally, it suggests a further research agenda.
The Impact of Dual and Triple Energy Window Scatter Correction on I-123 Postsurgical Thyroid SPECT/CT Imaging Using a Phantom with Small Sizes of Thyroid Remnants
Authors: Michael Konstantinos , Frangos Savvas , Iakovou Ioannis , Lontos Antonis , Demosthenous George , Parpottas Yiannis
Published: January 2024

I-123 is preferential over I-131 for diagnostic SPECT imaging after a thyroidectomy to determine the presence and size of residual thyroid tissue for radioiodine ablation. Scattering degrades the quality of I-123 SPECT images, primarily due to the penetration of high-energy photons into the main photopeak. The objective of this study was to quantitatively and qualitatively investigate the impact of two widely used window-based scatter correction techniques, the dual energy window (DEW) and triple energy window (TEW) techniques, in I-123 postsurgical SPECT/CT thyroid imaging using an anthropomorphic phantom with small sizes of remnants and anatomically correct surrounding structures. For this purpose, non-scatter-corrected, DEW and TEW scatter-corrected SPECT/CT acquisitions were performed for 0.5–10 mL remnants within a phantom, with 0.5–12.6 MBq administered activities within the remnants, and without and with background-to-remnant activity ratios of 5% and 10%. The decrease in photons, the noise and non-uniformity in the background region due to scatter correction were measured, as well as the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) from small remnants. The images were also visually evaluated by two experienced nuclear medicine physicians. Scatter correction decreased photons to a higher extent in larger regions than smaller regions. Larger remnants yielded higher SNR and CNR values, particularly at lower background activities. It was found from the quantitative analysis and the qualitative evaluation that TEW scatter correction performed better than DEW scatter correction, particularly at higher background activities, while no significant differences were reported at lower background activities. Scatter correction should be applied in I-123 postsurgical SPECT/CT imaging to improve the image contrast and detectability of small remnants within the background.
A Comparative Analysis of Multi-Scale and Rayleigh Approaches in Capturing Eigenfrequencies and Mode Shape Evaluation in Planetary Gear Transmission Systems of Medium and Heavy Trucks
Authors: Mabrouk Mahmoud , Gao Pu , Yan Keyu , Xie Yunkun , Yan Qi
Published: January 2024

Within planetary gear transmissions (PGTs), mode shapes and eigenfrequencies hold a crucial significance in operational reliability and efficacy. Mode shapes explain the unique motion patterns inherent in PGT systems. Conversely, eigenfrequencies describe the inherent frequencies at which PGT systems undergo vibration or oscillation upon exposure to external forces or disruptions. This research paper presents a comprehensive investigation into the dynamic behavior of a three-stage PGT utilized in medium and heavy trucks. This study introduces the Rayleigh energy method to assess system dynamics, revealing a bounded Rayleigh quotient related to the highest related eigenvalue. Then, this study delves into eigenfrequencies and the mode shape behavior of the adopted PGT model. The eigenfrequencies are identified as encompassing diverse vibrational modes of central components and planet gears. Moreover, a multi-scale analysis of the adopted PGT model is presented by deriving matrices for mass, bearing stiffness, and mesh stiffness. Comparisons with the Rayleigh energy method demonstrate the new approach’s efficiency, exhibiting a low margin of error in the determination of eigenfrequencies. This investigation also highlights the alignment of identified mode shapes with the established literature, detailing the multi-scale approach’s minor deviation in mode shape determination compared to the Rayleigh energy method.
Electric Cable Insulator Damage Monitoring by Lasso Regression
Authors: Zhang Qinghua , Drissi-Habti Monssef
Published: January 2024

Since the discovery of electricity, electric cables have become ubiquitous in human constructions, from machines to buildings. Insulators play a crucial role in ensuring the proper functioning of these cables, so it is important to monitor their possible damage, which can be caused by environmental contamination, severe temperature variations, and electrical and mechanical stress. While shunt conductance is a direct health indicator of cable insulation, measuring the cable average shunt conductance is not sufficient for the detection of localized insulator damage, since localized conductance variations are diluted over a long cable length in such measurements. The objective of this paper is to assess the feasibility of reflectometry techniques for the monitoring of insulator damage in electric cables. To this end, the estimation of localized conductance variations is investigated based on electrical measurements made at one end of a cable. To avoid estimating a large number of discretized conductance values along a long cable, the proposed method relies on sparse regression, which automatically focuses on localized conductance variations at unknown positions caused by accidental insulator damage. In order to efficiently apply sparse regression techniques, the telegrapher’s equations describing electric wave propagation in cables are transformed through several steps into a simple linear regression form. Then, Lasso (Least Absolute Shrinkage and Selection Operator) regression is applied to process the voltage and current data collected at a single end of the monitored cable. Numerical simulations show the potential of this method for fast estimation of localized shunt conductance variations.
Effect of Roller Burnishing and Slide Roller Burnishing on Surface Integrity of AISI 316 Steel: Theoretical and Experimental Comparative Analysis
Authors: Maximov Jordan , Duncheva Galya , Anchev Angel , Dunchev Vladimir , Anastasov Kalin , Daskalova Petya
Published: January 2024

The article presents a new method called slide roller burnishing (SRB) for the cold working of cylindrical surfaces on machine tools implemented with a novel multi-functional device. The machined material is chromium–nickel austenitic stainless steel. The deforming element is a toroidal roller whose axis crosses that of the workpiece. As a result, a relative sliding velocity occurs in the contact zone between the roller and the machined surface. The sliding velocity vector is set using the burnishing device. The theoretical background of SRB is presented. When the two axes are parallel, the well-known roller burnishing (RB) method is implemented. Thus, RB is a special case of SRB. Both processes are realized using the multi-functional burnishing device. The RB process was studied experimentally and optimized according to three criteria, based on the relationship between the surface integrity and operating behavior of the respective component, to achieve three processes: smoothing, hardening, and mixed burnishing. Using the optimal RB parameters obtained, the dependence of the results of SRB on the crossing angle was investigated and optimized. A comparative analysis was performed between the optimized RB and SRB processes (respectively for their three variants: smoothing, hardening, and mixed) based on geometrical and physical–mechanical characteristics of the surface integrity. The main advantage of the SRB is that it provides smaller height roughness parameters (improvement by 42%) and a higher surface microhardness (improvement by 7%) than RB.
Two Regularization Methods for Identifying the Spatial Source Term Problem for a Space-Time Fractional Diffusion-Wave Equation
Authors: Zhang Chenyu , Yang Fan , Li Xiaoxiao
Published: January 2024

In this paper, we delve into the challenge of identifying an unknown source in a space-time fractional diffusion-wave equation. Through an analysis of the exact solution, it becomes evident that the problem is ill-posed. To address this, we employ both the Tikhonov regularization method and the Quasi-boundary regularization method, aiming to restore the stability of the solution. By adhering to both a priori and a posteriori regularization parameter choice rules, we derive error estimates that quantify the discrepancies between the regularization solutions and the exact solution. Finally, we present numerical examples to illustrate the effectiveness and stability of the proposed methods.
Electrochemistry of Tin Deposition from Methanesulfonic Acid
Authors: Yang Yuantao , Wang Junli , Wang Xuanbing , Wei Jinlong , Tong Xiaoning , Xu Ruidong , Yang Linjing
Published: January 2024

The electrolytic refining of crude tin is generally carried out in the fluorosilicic acid (H2SiF6) system with the assistance of bone glue and β-naphthol. However, the high saturated vapor pressure and low stability of H2SiF6 present environmental concerns and do not align with sustainable development goals. In this paper, the electrochemical behavior of tin on a glassy carbon (GC) electrode was studied in a relatively green and environmentally friendly methanesulfonic acid (MSA) system. Bone glue, sodium lignosulfonate, and β-naphthol were used as additives to make the deposit morphology smooth and to ensure grain refinement. The electrochemical reduction process of Sn2+ in an MSA system is a quasi-reversible process controlled by diffusion. The apparent activation energy Ea = 14.189 kJ/mol for the ion diffusion of Sn2+ was further calculated. The results of chronoamperometry showed that the electrocrystallization of Sn2+ on the GC electrode gradually tended to three-dimensional instantaneous nucleation with the increase in applied potential. The morphology and phase of the deposits were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the deposits were uniform and dense pure tin. This work elucidates the electrochemical behavior of tin in a methanesulfonic acid system.
Corrosion Behavior of Nickel–Titanium Continuous-Casted Alloys
Authors: Lazić Minja Miličić , Mitić Dijana , Radović Katarina , Đorđević Igor , Majerič Peter , Rudolf Rebeka , Grgur Branimir N.
Published: January 2024

Variations in the corrosion behavior of biomedical NiTi alloys in Cl− containing and acidic environments present a problem with their biological implantation. The objective of this research was to evaluate the synergy of the microstructure, the corrosion behavior, and the biocompatibility of novel continuous-cast NiTi alloys and to compare them with commercial NiTi alloys. The two alloys have a practically identical nominal chemical composition, but they differ in production technology. The continuous casting technology involved vacuum induction melting of the basic components and vertical continuous casting, while the commercial NiTi alloy was produced through a process of casting, hot rolling, and forming into square shapes. The microstructure was revealed to determine the surface area and size of grains. The corrosion of a commercial nickel–titanium alloy and one prepared by a novel continuous casting method in acidic and chloride-containing solutions was studied via analytical and electrochemical tests. Localized corrosion characteristics related to oxide properties, when exposed to 9 g L−1 NaCl solution, were examined with focused ion beam analysis and subsequent microchemical analysis of the formed corrosive products. Corrosion potential over time and the oxide film resistance were analyzed using linear polarization measurements. To obtain a preliminary estimate of biocompatibility, human fibroblast cells were used in indirect contact, i.e., alloy conditioning medium. The continuous casting method resulted in a reduction in the average grain size in comparison to the commercial sample and better corrosion stability of the sample in an acidic environment. Also, in a solution of 9 g L−1 NaCl the commercial sample showed high values for the corrosion current density (jcorr = 6 μA cm−2), which indicated low corrosion resistance, while the continuous casting sample possessed much better corrosion stability and lower values for the corrosion current density (jcorr = 0.2 μA cm−2). In line with that, elemental analysis of the corroded surfaces showed higher Cl− ion deposition over the surface layer of the commercial sample, suggesting local oxide breakdown. Moreover, NiTicc reached a value three times higher for polarization resistance (Rp = 270 kΩ cm2) over time in comparison to the commercial sample (Rp~100 kΩ cm2). Biocompatibility evaluation showed that human fibroblast cells exhibited altered metabolic activity. An MTT assay showed that cells’ mitochondrial activity dropped below that of control cells in the presence of both materials’ supernatants.
Microsegregation Influence on Austenite Formation from Ferrite and Cementite in Fe–C–Mn–Si and Fe–C–Si Steels
Authors: Krugla Monika , Offerman S. Erik , Sietsma Jilt , Hanlon Dave N.
Published: January 2024

The production reality of sheet steels from casting to the end product is such that in the cases of ultra- and advanced high-strength steels, we have to deal with the segregation of elements on macro- and microlevels. Both can have a significant impact on the microstructure formation and resulting properties. There are several production stages where it can influence the transformations, i.e., casting, hot rolling process and annealing after cold rolling. In the present work, we focus on the latter, and more specifically, the transformation from ferrite–cementite to austenite, especially the nucleation process, in cold-rolled material. We vary the levels of two substitutional elements, Mn and Si, and then look in detail at the microsegregation and nucleation processes. The classical nucleation theory is used, and both the chemical driving force and strain energy are calculated for various scenarios. In the case of a high Mn and high Si concentration, the nucleation can thus be explained. In the cases of high Mn and low Si concentrations as well as low Mn alloys, more research is needed on the nuclei shapes and strain energy.
Design of a Micro-Electro Mechanical System Quad Mass Gyroscope with Compliant Mechanical Amplification
Authors: Zhou Jingchuan , Xu Dacheng , Li Xinxin , Chen Fang
Published: January 2024

In this work, a novel mechanical amplification structure for a MEMS vibratory gyroscope is proposed with the aim of improving their sensitivity. The scheme is implemented using a system of micromachined V-shaped springs as a deflection amplifying mechanism. The effectiveness of the mechanism is first demonstrated for a capacitive fully decoupled quad mass gyroscope. A proof of concept vertical-axis mechanically amplified gyroscope with an amplification factor of 365% has been designed, simulated and fabricated, and results from its evaluation are presented in this paper. Experimental results show that the natural frequency of the gyroscope is 11.67 KHz, and the full scale measurement range is up to ±400°/s with a maximum nonlinearity of 54.69 ppm. The bias stability is 44.53°/h. The experiment results show that this quad mass gyroscope’s performance is a very potential new way of reaching the navigation grade in the future.
Diversity of Microbial Mats in the Makgadikgadi Salt Pans, Botswana
Authors: Filippidou Sevasti , Price Alex , Spencer-Jones Charlotte , Scales Anthony , Macey Michael C. , Franchi Fulvio , Lebogang Lesedi , Cavalazzi Barbara , Schwenzer Susanne P. , Olsson-Francis Karen
Published: January 2024

The Makgadikgadi Salt Pans are the remnants of a mega paleo-lake system in the central Kalahari, Botswana. Today, the Makgadikgadi Basin is an arid to semi-arid area receiving water of meteoric origin during the short, wet season. Large microbial mats, which support primary production, are formed due to desiccation during the dry season. This study aimed to characterise the microbial diversity of the microbial mats and the underlying sediment. The focus was the Ntwetwe Pan, located west of the Makgadikgadi Basin. Metagenomic analyses demonstrated that the mats consisted of a high relative abundance of Cyanobacteriota (synonym Cyanobacteria) (20.50–41.47%), Pseudomonadota (synonym Proteobacteria) (15.71 to 32.18%), and Actinomycetota (synonym Actinobacteria) (8.53–32.56%). In the underlying sediments, Pseudomonadota, Actinomycetota, and Euryarchaeota represented over 70% of the community. Localised fluctuations in water content and pH did not significantly affect the microbial diversity of the sediment or the mats.
Study of a Novel Fluidized Bed Flotation Column with Enhanced Bubble Dispersion
Authors: Yin Mao , Han Ning , Yang Ting , Li Yanfeng
Published: January 2024

Flotation machines and flotation columns are widely used as separation equipment for coal sludge. In order to obtain better flotation results for different particle sizes, the bubble distribution and size in the flow field need to be studied. In this paper, a novel three-phase fluidized bed flotation column (TFC) was designed, and the shear effect of liquid velocity (0.198 m/s, 0.226 m/s, and 0.254 m/s) and static bed height (0.1 m, 0.2 m, and 0.3 m) on the bubbles in the mineralized flow field region was investigated and evaluated for the formation of bubbles by shear in laboratory and semi-industrial experiments. The results show that the increase in filling bed height has a very obvious strengthening effect on the reduction of bubble diameter, and after the filling bed height reaches a certain value, the filling bed height will weaken the effect of apparent gas velocity on bubble diameter. The apparent gas velocity has different influencing effects on bubble diameter, and under conditions of low water velocity, the increase in the apparent gas velocity contributes to the reduction of bubble diameter. The conclusions of this study are expected to optimize the operating parameters of the flotation mineralization process and enrich the study of TFC, which can provide a reference for the design of future TFC studies.
Hydrothermal Mineralization and Mineral Chemistry of Arsenides and Sulfarsenides in the Fe-Co-Ni-As-S System and Introduction of Three Unique Minerals, Port Radium Deposit, Canada
Authors: Somarin Alireza K. , Zhou Li , Zheng Guodong , Ma Xiangxian
Published: January 2024

The Port Radium U-Cu-Ni-Co-Ag deposit in northwestern Canada is hosted within a mineral system that has generated a variety of mineralization styles from iron oxide-copper-gold to iron oxide-apatite, porphyry, skarn, and epithermal. Their genesis is linked to an extensive subduction-related magmatism that formed widespread dacite-rhyodacite-andesite volcanic and volcanoclastic sequences (~1.87 Ga), which have been intruded by their equivalent intrusive plutons. Pervasive and intensive hydrothermal alterations, including albitic, magnetite-actinolite-apatite, potassic ± albitic, phyllic, and propylitic occurred before the main sulfide, sulfarsenide, and uraninite vein-type mineralization. Although scarce sulfide minerals formed at the beginning of the hydrothermal activity, the main polymetallic arsenide-sulfarsenide-sulfide ± uraninite vein-type mineralization occurred during the epithermal stage. In addition to the common arsenides and sulfarsenides including nickeline, cobaltite, rammelsbergite, safflorite, skutterudite, gersdorffite, and arsenopyrite, three unique sulfarsenides were also found: Co0.67Ni0.32Fe0.02S0.19As2.80, which could be a sulfur-rich skutterudite, Ni0.85Co0.15S0.39As1.60, and Ni0.69Co0.31S0.47As1.52, which are chemically comparable to the Port Radium rammelsbergite with substantial addition of S and Co; they could be the solid solution product of gersdorffite-cobaltite or safflorite-rammelsbergite.
Studying the Flotation of Gold-Bearing Ores Using Carrier Minerals
Authors: Evdokimov Sergei Ivanovich , Golikov Nikolay S. , Zadkov Denis A. , Voitovich Elena V. , Kondratiev Viktor V. , Petrovskiy Aleksey A. , Konyukhov Vladimir Yu. , Gladkikh Vitaliy A.
Published: January 2024

This work is aimed at the analysis of the development of flotation technology by applying carrier minerals. Based on the concepts of continuum mechanics, a theoretical analysis of the influence of the carrier minerals (wall) on the motion of a single solid particle is provided, taking into account their hydrodynamic interaction (in the case of low Reynolds numbers). A correction was obtained in the form of a ratio of the particle size to its distance from the wall to take into account the influence of the wall on the hydrodynamic force acting on the particle. The influence of the wall is manifested through a rapid approximation of the liquid vortex flow in the gap between the solid wall and the particle to the steady-state mode, accompanied by the suppression of the transverse movement of particles. When the liquid slides along a wall-mounted gas–liquid layer with a reduced viscosity, the liquid flow increases in the interfacial gap, which can be analyzed by a dimensionless correction that includes values describing the properties of a continuous medium (dynamic viscosity) and a disperse phase (geometric particle size). The reason for the decrease in the induction time when gold grains adhere to each other is assumed to be due to the forces of hydrophobic attraction (when the grains have a mirror-smooth surface) and the sliding of the flow along the hydrophobic surface of the particles along the gas layer (when the grains have a rough surface). When polydisperse particles are aggregated, the threshold energy of the fast coagulation was established to be lower than that arising during the interaction of monodisperse particles, whose aggregation requires a large depth of the potential pit. Performing natural experiments on the ore using a rougher concentrate as a carrier material showed that the concentrate yield decreases by 20.52% rel. In the second case, the gold extraction was higher by 4.69% abs. While maintaining the achieved level of gold extraction, the double mixing of the rougher concentrate and the initial feed increased the gold content in the rougher concentrate from 4.97 to 6.29 g/t.