Article
Engineering, Mechanical
V Gray, J. P. Jones, M. T. Whittaker, R. J. Lancaster, C. J. Pretty, S. J. Williams
Summary: This study focuses on the TMF behavior of aerospace nickel based superalloy RR1000, proposing an elastic modulus normalization technique to predict material life, with a specific emphasis on the impact of phase angle in TMF lifing.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Michal Bartosak, Jakub Horvath, Zdenek Pitrmuc, Marie Rohlova
Summary: The phase angle in TMF tests has a significant influence on the dominant damage mechanism and observed lifetime. A modified damage model has been proposed to account for the effect of the phase angle.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Nanoscience & Nanotechnology
Yingjun Jiao, Guangmin Sheng, Yuntao Zhang, Chuan Xu, Xinjian Yuan
Summary: The effects of Ni-Cr-B interlayer material on the transient liquid phase (TLP) bonding of Inconel 625 with Mar-M247 superalloy were investigated. It was found that the mechanical properties of the joints were closely related to the number, size, and location of the precipitated borides, with a considerable amount of large borides leading to a decrease in mechanical properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Jingyu Sun, Shun Yang, Huang Yuan
Summary: The study shows that the lifetime of nickel-based single-crystal superalloy CMSX-4 under thermo-mechanical fatigue and thermal gradient mechanical fatigue loading conditions is significantly affected by temperature gradient. Conventional fatigue models fail to accurately describe this, emphasizing the need to consider temperature gradient and thermal-mechanical phase angle effects.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
M. L. Hendery, M. T. Whittaker, B. J. Cockings, P. M. Mignanelli
Summary: This paper describes a study on hot corrosion damage in the nickel-based gas turbine alloy RR1000 coated with various salts at 600°C. The results show that sulphate has a greater impact on fatigue life, while chloride influences crack initiation behavior.
Article
Engineering, Mechanical
Xinxin Qi, Tianqi Liu, Xinhong Shi, Jiaying Wang, Jianyu Zhang, Binjun Fei
Summary: A stress-based sectional critical plane model is proposed to predict fatigue life under multiaxial constant amplitude loading, considering material properties and loading paths. The model divides critical planes into three sections based on the ratio of maximum shear stress amplitude to maximum normal stress amplitude. Experimental data support the strong applicability of the model for steel, aluminum, and titanium alloy materials, especially under multiaxial loadings with mean stresses. Prediction results show that the proposed model performs better than commonly used criteria for steel materials.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Qiang Zhang, Xiaoan Hu, Ziruo Zhang, Tong Sun, Jinwu Wu, Yifan Li, Tingting Ren
Summary: The mechanical properties of a TiAl alloy under combined tension-torsion fatigue loadings were investigated, and the correspondence between multiaxial fatigue life and failure behavior was explored. The S-L fatigue criterion was critically reviewed and modified, with the introduction of a correction factor to make the MWCM method feasible for multiaxial fatigue life prediction. Experimental results showed the proposed method to be accurate compared to Matake method and McDiarmid method.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Optics
Jiaye Zhao, Yiyang Li, Hongye Zhang, Zhanwei Liu, Huimin Xie, Sheng Liu
Summary: In this study, a modified integrated digital image correlation (I-DIC) method is developed to characterize the thermo-mechanical properties of nickel-based single crystal superalloys. Particle Swarm Optimization (PSO) and Gradient-Based optimization algorithm are introduced to the modified I-DIC method. The results show that the parameters vary with temperature, with the coefficient of thermal expansion (CTE) and Poison's ratio increasing and Young's modulus and shear modulus decreasing with increasing temperature.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Mechanical
V. Shlyannikov, A. Sulamanidze
Summary: This study developed a computational strategy to simulate the thermo-mechanical fatigue behavior of crack tip fields under in-phase and out-of-phase loading histories. By employing a multi-physics numerical calculation algorithm, the mechanics of crack tip deformation under thermo-mechanical loading conditions were analyzed. The proposed algorithm was applied to polycrystalline nickel-based alloys and demonstrated the influence of mechanical loading, temperature, and material properties on crack growth.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
J. Telesman, T. P. Gabb, P. T. Kantzos, L. J. Ghosn
Summary: The study examined the influence of various broaching machining parameters on the high temperature fatigue lives of a nickel-based disk alloy, quantifying the effects of tool wear and broaching speed on residual stresses, cold work, and surface roughness. These variables were found to have a substantial impact on fatigue lives, failure mode types, and fatigue crack initiation mechanisms. Statistical analyses were used to evaluate these relationships.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Anoop Vasu, Jifa Mei, Jerry Chung, Yogesh Mehta
Summary: This research aims to predict the fatigue life of carburized 4320 steel shafts by creating hardness-based strain-life curves and considering mean stress correction. An analytical model was proposed to explain the experimental data, and Weibull statistics-based reliability estimation was implemented to determine the design bounds for the carburized pinion shaft.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
C. Z. Zhu, R. Zhang, C. Y. Cui, Y. Z. Zhou, Y. Yuan, Z. S. Yu, X. Liu, X. F. Sun
Summary: This study investigates the effect of adding tantalum on the tensile properties of a nickel-cobalt base superalloy in a range of temperatures. Results show that tantalum addition improves the alloy's strength at all temperatures and enhances plasticity at 760°C. Microstructural observations reveal that tantalum promotes the precipitation of specific phases and carbides, influencing the alloy's deformation and fracture mechanisms. Moreover, the alloy's strength and plasticity enhancement at 760°C can be attributed to a combination of factors including increased grain boundary strength, reduced resolved shear stress, and twinning promotion.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Engineering, Mechanical
V. Shlyannikov, A. Sulamanidze, D. Kosov
Summary: This paper presents experimental crack-growth data for thermomechanical fatigue conditions in nickel-based alloy components. The crack-growth experimental results are interpreted using finite element analyses and multi-physics numerical calculations. The results show that crack growth rate is slower under isothermal pure fatigue conditions, while it is faster under thermomechanical cyclic deformation conditions.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Chemistry, Physical
Jianxing Mao, Zhixing Xiao, Dianyin Hu, Xiaojun Guo, Rongqiao Wang
Summary: This paper systematically investigates the creep-fatigue crack growth behavior of the nickel-based superalloy GH4720Li under different temperature, stress ratio, and dwell time conditions. A concise binomial crack growth model is proposed and validated, which accurately predicts the experimental data.
Article
Materials Science, Multidisciplinary
Yong-Qiang Wang, Chao Yuan, Bing Zhang, Xin-Yu Gao, Shi-Chang Qiao, Xin Wen, Yi-Peng Chen, Feng-Zhen Wang
Summary: This study investigates the deformation mechanisms of GH3536 superalloy during loading by conducting tensile tests and interrupted experiments at different temperatures. The microstructure evolutions and dislocation densities of the alloy were studied using TEM and XRD. Deformation twins were observed at 77K, while deformation occurred solely by dislocation slip at 293K. The competition between the maximum flow stress and critical stress for twinning determines the deformation mechanisms of GH3536 alloy. Twinning provides an additional deformation mode, resulting in improved ductility and strength at 77K compared to 293K.
MATERIALS CHARACTERIZATION
(2023)
Article
Anesthesiology
Daniel Martins, Ottavia Dipasquale, Mattia Veronese, Federico Turkheimer, Marco L. Loggia, Stephen McMahon, Matthew A. Howard, Steven C. R. Williams
Summary: This study examines alterations in morphometric similarity in chronic pain patients and identifies genetic and cellular correlates of these changes. The findings suggest that cortical remodeling in chronic pain may be influenced by multiple elements of the brain's cellular architecture and highlight potential pathways for future genetic association or drug development studies.
Article
Psychology, Clinical
Tanja Jaeckle, Steven C. R. Williams, Gareth J. Barker, Rodrigo Basilio, Ewan Carr, Kimberley Goldsmith, Alessandro Colasanti, Vincent Giampietro, Anthony Cleare, Allan H. Young, Jorge Moll, Roland Zahn
Summary: Self-guided psychological intervention with additional fMRI neurofeedback targeting self-blaming emotions showed potential in reducing symptoms in non-anxious MDD patients. However, further studies are needed to confirm these findings.
PSYCHOLOGICAL MEDICINE
(2023)
Editorial Material
Radiology, Nuclear Medicine & Medical Imaging
Giovanna Nordio, Gill Brown, Sagar Jilka, Alexander Hammers, Mitul A. Mehta, Anoushka Leslie, Steve Williams, Mattia Veronese
CLINICAL AND TRANSLATIONAL IMAGING
(2022)
Article
Industrial Relations & Labor
Saja Albelali, Steve Williams
Summary: This paper investigates the implications of the Nitaqat policy on gendered power relations in the workplace. The increased feminization of employment under Nitaqat has provided women workers with access to power resources and influenced the dynamics of gendered power relations in Saudi workplaces.
EMPLOYEE RELATIONS
(2022)
Article
Immunology
D. Martins, O. Dipasquale, K. Davies, E. Cooper, J. Tibble, M. Veronese, M. Frigo, S. C. R. Williams, F. Turkheimer, M. Cercignani, N. A. Harrison
Summary: Systemic inflammation induces acute changes in mood, motivation, and cognition that resemble depressive symptoms. This study investigated the effects of two treatments on brain function and identified potential pathways linking inflammation to psychopathology. The results showed that interferon-alpha and anti-TNF therapies both caused decreases in regional brain connectivity, but within different brain regions and through distinct transcriptomic vulnerability patterns. This finding suggests possible brain mechanisms through which changes in peripheral inflammation contribute to the development or resolution of psychopathology.
BRAIN BEHAVIOR AND IMMUNITY
(2022)
Article
Neurosciences
Marina Charquero-Ballester, Birgit Kleim, Diego Vidaurre, Christian Ruff, Eloise Stark, Jetro J. Tuulari, Hugh McManners, Yair Bar-Haim, Linda Bouquillon, Allison Moseley, Steven C. R. Williams, Mark W. Woolrich, Morten L. Kringelbach, Anke Ehlers
Summary: The study detected recurring large-scale brain functional states with high temporal precision in healthy trauma-exposed individuals and PTSD patients before and after successful CT-PTSD treatment. It was found that PTSD patients spent less time on specific default mode subnetworks after treatment, suggesting a rebalance in the dynamic aspect of brain function related to self-referential processes and threat detection.
HUMAN BRAIN MAPPING
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Emil Ljungberg, Tobias C. Wood, Ana Beatriz Solana, Steven C. R. Williams, Gareth J. Barker, Florian Wiesinger
Summary: This study developed a self-navigated motion correction method for 3D silent ZTE-based neuroimaging and characterized its performance for different types of head motion. The results showed that MERLIN achieved successful and consistent motion correction for various instructed motion paradigms.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Sean C. L. Deoni, Jonathan O'Muircheartaigh, Emil Ljungberg, Mathew Huentelman, Steven C. R. Williams
Summary: Low magnetic field systems provide an important opportunity for expanding MRI to new clinical and research study populations. However, they have lower signal-to-noise ratios compared to higher field strength systems, resulting in compromises in spatial resolution and imaging time. This study introduces a super-resolution approach to reconstruct high-resolution T-2-weighted images from low-resolution anisotropic images acquired in orthogonal orientations, allowing for simultaneous quantitative T-2 imaging without sacrificing time. The results demonstrate the feasibility and accuracy of this approach in acquiring high-resolution images and quantitative T-2 maps.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Chemistry, Physical
Jennie Palmer, Jonathan Jones, Mark Whittaker, Steve Williams
Summary: A bespoke TMF crack growth test set-up was developed and validated for this study, and the effects of phasing between mechanical loading and temperature were investigated. The study revealed that TMF cycles may exhibit increased crack growth rate behavior compared to isothermal fatigue. The phase angle of the applied TMF cycle also influenced crack growth behavior, with in-phase (IP) conditions showing faster crack growth rates than out-of-phase (OP) conditions. Propagating cracks interacted with the microstructure of the material, particularly the alpha/beta interfaces within the prior beta grains, and supporting fractography demonstrated subtle differences in fracture mechanisms due to phase angle.
Review
Rheumatology
Jennifer G. Cox, Marius de Groot, James H. Cole, Steven C. R. Williams, Matthew J. Kempton
CLINICAL RHEUMATOLOGY
(2023)
Article
Neurosciences
Marie-Stephanie Cahart, Owen O'Daly, Vincent Giampietro, Maarten Timmers, Johannes Streffer, Steven Einstein, Fernando Zelaya, Flavio Dell'Acqua, Steven C. R. Williams
Summary: This study compared the reliability of conventional single-band fMRI and different multiband (MB) fMRI acquisitions with and without in-plane acceleration across multiple scanning sessions. It found that for cortical areas, MB factor 4 without in-plane acceleration had the highest reliability, while for subcortical areas, conventional single-band fMRI was more reliable.
HUMAN BRAIN MAPPING
(2023)
Article
Engineering, Mechanical
M. T. Whittaker, N. C. Barnard, B. J. Cockings, E. Duffy, S. J. Williams, M. C. Hardy
Summary: This study investigates the effect of melt anomalies on the overall lifing approaches for RR1000 alloy. It is found that hard particle inclusions dominate fatigue failures at long fatigue lives, while failure occurred at the peened surface for shorter fatigue lives.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Editorial Material
Biochemistry & Molecular Biology
Caroline D. Rae, Stephen R. Williams
Summary: The ISMRM study group has made recommendations for reporting methods in magnetic resonance spectroscopy and the Journal of Neurochemistry has decided to promote the use of a checklist based on these standards. This aims to enhance reproducibility and reliability of scientific research, facilitate the work of reviewers, and contribute to the education of the scientific community.
JOURNAL OF NEUROCHEMISTRY
(2023)
Article
Neurosciences
Timothy Lawn, Daniel Martins, Owen O'Daly, Steve Williams, Matthew Howard, Ottavia Dipasquale
Summary: Placing a patient under anesthesia is crucial in surgical practice, but the mechanisms by which anesthetic drugs affect consciousness are poorly understood. Using REACT, a multi-modal imaging technique, this study investigated how different levels of propofol-induced sedation affect neurotransmission-related functional connectivity. The results showed that propofol increased GABA-A and noradrenaline transporter-enriched functional connectivity in occipital and somatosensory regions, respectively. During auditory stimulation, the dopaminergic network exhibited reduced functional connectivity, particularly in bilateral temporal and mid/posterior cingulate cortices, with an interaction between auditory stimulation and level of consciousness observed in the right temporal cluster. By integrating micro- and macro-scale systems, this study provides evidence for direct GABAergic and indirect noradrenergic and dopaminergic-related network changes under propofol sedation, highlighting the utility of REACT in exploring the molecular substrates of consciousness and cognition.
Article
Oncology
Steven C. R. Williams, Ndaba Mazibuko, Owen O'Daly, Christian Zurth, Fiona Patrick, Christian Kappeler, Iris Kuss, Patricia E. Cole
Summary: This study compared the effects of two androgen receptor inhibitors, darolutamide and enzalutamide, and placebo on blood flow in the brain. Enzalutamide reduced cerebral blood flow, while darolutamide did not significantly affect it.