The structural, optical and photovoltaic properties of Zn-doped MAPbI2Br perovskite solar cells.

The spin coating method was used to deposit MAPbI2Br films on FTO-glass substrates. Zn2+ (zinc) doping was used for these films at intensity rates of 2% and 4%, respectively. XRD analysis proved that MAPbI2Br films had a cubic structure and a crystalline character. 2% Zn doping into the MAPbI2Br film had a modest large grain size (38.09 nm), Eg (1.95 eV), high refractive index (2.66), and low extinction coefficient (1.67), according to XRD and UV-vis analyses. To facilitate and enhance carrier transit, at contacts as well as throughout the bulk material, the perovskite's trap-state densities decreased. The predicted MAPbI2Br valence and conduction band edges are -5.44 and -3.52, respectively. The conduction band (CB) edge of the film that was exposed to Zn atoms has been pressed towards the lower value, assembly it a better material for solar cells. EIS is particularly useful for understanding charge carrier transport, recombination mechanisms, and the influence of different interfaces within the device structure. Jsc is 11.09 mA cm-2, Voc is 1.09, PCE is 9.372% and FF is 0.777. The cell made with the 2% Zn doped into the MAPbI2Br film demonstrated a superior device.

Unveiling Disparities: Exploring Differential Attainment in Postgraduate Training Within Clinical Oncology.

AIMS: Differential attainment (DA) in post graduate medical training is a recognised challenge and refers to unexplained variation across groups when split by several protected characteristics. The Royal College of Radiology is committed to fostering diversity, inclusivity, and equality with the goal of narrowing existing gaps and improving training outcomes. MATERIALS AND METHODS: This was a mixed methods study aiming to understand the causes of DA with view to helping the RCR develop strategies to address this. A cross-sectional survey was completed by 140 clinical oncology trainees in September 2022. Trainees and trainers (17 and 6 respectively) from across England, Scotland, Wales and Northern Ireland, took part in focus group and interviews from August to December 2022. Quantitative and qualitative data merged and interpreted. RESULT: Results showed international medical graduates and trainees from ethnic minority backgrounds were more likely to encounter challenges. The qualitative findings were used to identify three themes through which these problems could be framed. The trainee as a "space invader," the hidden curriculum of clinical oncology training and the process of navigating and tacking the training journey. CONCLUSION: Differential attainment is the product of a complex interplay between the trainee, trainer, and the training environment. Therefore, interventions must be tailored to different people and contexts. At a national level, the RCR can adopt general policies to promote this such as mentorship programmes, protected time for supervision and cultural competency training. Efficacy of proposed interventions for trial and their impact on DA should be evaluated to drive evidence-based changes.

Factors affecting the choice of medical specialties in Turkiye: an analysis based on cross-sectional survey of medical graduates.

BACKGROUND: Modern healthcare systems require the right mix of medical specialties for effective provision of high-quality services. Despite increased availability of general physicians and specialists, Türkiye lags behind high-income countries in terms of availability of specialists. The purpose of the study is to identify several specific factors that affect the choice of medical specialization. METHODS: All 350 medical school graduates in a specialty examination preparation bootcamp were requested to participate in the survey and 333 completed the self-administered questionnaire. The survey asked questions about factors affecting choice of medical specialty by medical graduates. RESULTS: The empirical results indicate that surgical specialties, compared to other broad medical specializations, are selected because of its higher income-earning potential and social prestige. The likelihood of selecting surgical specialties is negatively affected by rigorousness of the training program, high work-load, risk of malpractice lawsuits and risk of workplace violence. Male participants were 2.8 times more likely to select surgery specialty compared to basic medical science. Basic medical science areas were selected at a higher rate by female graduates and graduates with high level of academic performance in medical schools. CONCLUSIONS: It is critically important to improve trust and inter-personal communications between the patients and physicians in all specialties to lower the likelihood of malpractice lawsuits and workplace violence. Policy-makers may adopt policies to affect income earning potential and social prestige of targeted specializations to improve their supply.

A Vehicle-Edge-Cloud Framework for Computational Analysis of a Fine-Tuned Deep Learning Model.

The cooperative, connected, and automated mobility (CCAM) infrastructure plays a key role in understanding and enhancing the environmental perception of autonomous vehicles (AVs) driving in complex urban settings. However, the deployment of CCAM infrastructure necessitates the efficient selection of the computational processing layer and deployment of machine learning (ML) and deep learning (DL) models to achieve greater performance of AVs in complex urban environments. In this paper, we propose a computational framework and analyze the effectiveness of a custom-trained DL model (YOLOv8) when deployed in diverse devices and settings at the vehicle-edge-cloud-layered architecture. Our main focus is to understand the interplay and relationship between the DL model's accuracy and execution time during deployment at the layered framework. Therefore, we investigate the trade-offs between accuracy and time by the deployment process of the YOLOv8 model over each layer of the computational framework. We consider the CCAM infrastructures, i.e., sensory devices, computation, and communication at each layer. The findings reveal that the performance metrics results (e.g., 0.842 mAP@0.5) of deployed DL models remain consistent regardless of the device type across any layer of the framework. However, we observe that inference times for object detection tasks tend to decrease when the DL model is subjected to different environmental conditions. For instance, the Jetson AGX (non-GPU) outperforms the Raspberry Pi (non-GPU) by reducing inference time by 72%, whereas the Jetson AGX Xavier (GPU) outperforms the Jetson AGX ARMv8 (non-GPU) by reducing inference time by 90%. A complete average time comparison analysis for the transfer time, preprocess time, and total time of devices Apple M2 Max, Intel Xeon, Tesla T4, NVIDIA A100, Tesla V100, etc., is provided in the paper. Our findings direct the researchers and practitioners to select the most appropriate device type and environment for the deployment of DL models required for production.

Study of Serum Electrolytes (Sodium and Potassium) Abnormalities in Acute Stroke.

Stroke is the common cause of death and disability worldwide, as well as in Bangladesh. Serum electrolytes abnormalities or dyselectrolytaemia is one of the major acute complications of stroke. Dyselectrolytaemia or serum electrolytes (sodium and potassium) abnormalities are more common in patients with acute stroke that can be easily measured. The study was planned to find out the serum electrolytes (sodium and potassium) abnormalities in acute stroke patients. This cross-sectional study was conducted in the Department of Neurology and Medicine, Mymensingh Medical College and Hospital from January 2019 to June 2020. Total 84 purposively selected patients with acute strokes were evaluated following informed written consent. Diagnosis was confirmed by neuroimaging of brain. Moreover, serum electrolytes level was measured for each patient. Data were collected by interviews, clinical examinations & laboratory investigations of the patients using a case record form and analysis was carried out by the help of SPSS 25.0. Mean age of the patients with acute strokes were 57.65±15.79 years. About two thirds (60.7%) of the patients were male and the remaining (39.3%) were female. Sodium imbalances were observed in 32.2% and potassium imbalances in 25.0% cases. About 66.7% haemorrhagic strokes patients and 42.2% ischaemic strokes patients had dyselectrolytaemia (p<0.05). More than twenty eight percent (28.6%) of all stroke patients had hyponatraemia, which was more common (35.9%) among haemorrhagic strokes patients (p<0.05). Of all stroke patients 21.4% had hypokalaemia, which was more common (28.2%) in haemorrhagic strokes patients (p<0.05). This study reveals that, serum electrolytes (sodium and potassium) abnormalities are more common in haemorrhagic than ischaemic strokes, which is mainly hyponatraemia and hypokalaemia.

Demographic and Clinical Characteristics of Functional Dyspepsia and Its Subtypes in Adult Patients: An Experience from a Tertiary Care Centre in Bangladesh.

Functional dyspepsia (FD) is a common gastrointestinal problem in the world. The Rome III consensus subdivided functional dyspepsia into two groups: meal-related postprandial distress syndrome (PDS) and meal-unrelated epigastric pain syndrome (EPS). Limited data are available regarding FD in Bangladesh. The aim of this study was to investigate the demographic and clinical characteristics of FD and its sub-types. This cross-sectional study was conducted in which we recruited patients who attended the outpatient department of Gastroenterology of Bangabandhu Sheikh Mujib Medical University, Bangladesh from March 2017 to February 2018. Patients fulfilling Rome III FD criteria and a negative upper GIT endoscopy were included for this study. The patients were then subdivided into 'pure' PDS (i.e. meeting criteria for PDS without EPS symptoms), 'pure' EPS (i.e., meeting criteria for EPS without PDS symptoms), and overlapping PDS-EPS (i.e., symptoms of both PDS and EPS) groups. Total of 368 FD patients (56.0% females, mean age 32.8±8.6 years, BMI: 22.0±2.7), were included in this study. Out of them, 112(30.4%) patients (57.2% females, mean age 33.9±9.3 years, BMI: 22.0±2.7) fulfilled criteria of pure EPS and 64(17.4%) patients (68.8% females, mean age 33.2±7.8 years, BMI: 22.1±2.4) fulfilled criteria of pure PDS. However, the majority of patients [192(52.2%), 52.1% females, mean age 32.0±8.4 years, BMI: 21.9±2.8] had symptoms of overlapping EPS-PDS. More than 40% of patients in our study presented with 3 or more of the four key symptoms of FD. A longer duration of presenting symptoms was seen among patients with overlapping EPS-PDS in comparison to pure EPS and pure PDS (p<0.001). A significant overlap of symptoms of both EPS and PDS was noticed among patients with FD. The value of dividing functional dyspepsia into the subgroups of PDS and EPS is thus questionable. Further research and modification of the diagnostic criteria for FD subtypes are necessary.

Serum Uric Acid and Serum Lipid Levels in Patients with Acute Ischemic Stroke Admitted in Mymensingh Medical College Hospital.

Stroke is the second-leading cause of death and also a leading cause of combined death and disability. In Bangladesh, stroke prevalence is 11.39 per 1000 population, but highest prevalence of stroke is 14.71 per 1000 population in the Mymensingh division. Hyperuricemia has been reported as an independent risk factor for stroke in different studies and a significant association between serum uric acid and dyslipidemia has also been stated. On the contrary, some studies suggest that uric acid has a neuroprotective role. This cross-sectional study was completed in the Medicine Department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh from March 2021 to January 2023. In this cross-sectional study, 352 adult acute ischemic stroke patients were included from the Medicine Department of Mymensingh Medical College Hospital. Serum uric acid and fasting serum lipid levels were measured within 48 hours of admission. The mean age ±SD of the respondents was 61.9±12.8 years. Hyperuricemia was found among 18.2% of respondents, whose mean ±SD serum uric acid was 5.7±1.9 mg/dl. Dyslipidemia was present in 88.4% of patients. The mean ±SD of the National Institutes of Health Stroke Scale (NIHSS) score was 12.0±5.9. Most of the patients (65.6%) were suffering from moderate stroke, followed by moderate to severe stroke (15.1%), severe stroke (10.8%) and minor stroke (8.5%). After multiple linear regressions, the independent variables age, gender, serum uric acid and total cholesterol were found to be significant predictors of the NIHSS score of the respondents. In conclusion, the majority of acute ischemic stroke patients have an association with dyslipidemia, but only around one-fifth of patients have hyperuricemia. There is a significant association of high serum uric acid and high serum total cholesterol with stroke severity (NIHSS score). But low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and, triglycerides have no association with stroke severity.

Clinical Profile and Outcome of Organophosphorus Poisoning in a Tertiary Hospital.

Organophosphorus compound (OPC) poisoning is common in Bangladesh. The toxicity of the agent and paucity of appropriate medical services has resulted in high mortality rates. To find out the clinical profile and outcome of OPC poisoning patients is the main aim of my study. This descriptive cross-sectional study was conducted in the Department of Medicine, Mymensingh Medical College Hospital, Bangladesh from September 2016 to November 2018. In this study, mean age of the study subjects was 25.90±11.24 years. Males (70.8%) were predominant than female (29.2%). In this study, most of the poisoning was done by ingestion (98.3%) and only two (1.7%) by inhalation. Regarding features, most muscarinic effect was constricted pupil and bronchospasm (65.0%). Common nicotinic effect was fasciculation (25.0%) and central effect was headache (61.67%). Mean amount of OPC ingestion was 26.30±17.24 ml in this study. Regarding circumstances of poisoning, familial disharmony (38.3%) and quarrel with other family members (37.5%) were the major reason followed by failure of personal affairs (15.0%) and other reasons (9.2%). Regarding complications, aspiration pneumonia was found in 6.7% cases, cardiac arrhythmia was in 6.7% cases and intermediate syndrome was in 1.7% cases. Most of the study subjects (95.0%) recovered fully. Most of the patients were from rural area. Suicidal was the common motive and familial disharmony and quarrel with other family members are the common circumstances of poisoning. Mortality rate was 5.0%.

Silicon nanoparticles vs trace elements toxicity: Modus operandi and its omics bases.

Phytotoxicity of trace elements (commonly misunderstood as 'heavy metals') includes impairment of functional groups of enzymes, photo-assembly, redox homeostasis, and nutrient status in higher plants. Silicon nanoparticles (SiNPs) can ameliorate trace element toxicity. We discuss SiNPs response against several essential (such as Cu, Ni, Mn, Mo, and Zn) and non-essential (including Cd, Pb, Hg, Al, Cr, Sb, Se, and As) trace elements. SiNPs hinder root uptake and transport of trace elements as the first line of defence. SiNPs charge plant antioxidant defence against trace elements-induced oxidative stress. The enrolment of SiNPs in gene expressions was also noticed on many occasions. These genes are associated with several anatomical and physiological phenomena, such as cell wall composition, photosynthesis, and metal uptake and transport. On this note, we dedicate the later sections of this review to support an enhanced understanding of SiNPs influence on the metabolomic, proteomic, and genomic profile of plants under trace elements toxicity.

Iatrogenic Venous Compression Syndrome Following Bilateral Hip Arthroplasty: A Unique Case of Bilateral Femoral Vein Compression in a Patient With May-Thurner Syndrome.

Iatrogenic venous compression syndrome is defined by extrinsic vein compression due to medical hardware, particularly relevant after joint replacement surgeries. Inserting medical hardware can lead to immediate risks such as deep vein thrombosis and pulmonary embolisms due to local tissue inflammation. The long-term issues include venous insufficiency due to chronic vessel irritation, subsequently causing intimal proliferation and thickening. Despite the existing knowledge of venous compression syndromes, iatrogenic cases are severely underreported. Here, we present a unique case of bilateral common femoral vein compression in a patient with May-Thurner syndrome and prior bilateral hip arthroplasty. An 85-year-old man with a history of venous insufficiency and bilateral hip arthroplasty for osteoarthritis presented with bilateral leg edema. Unsuccessful sclerotherapy and radiofrequency ablation led to a referral to a vascular specialist for venous duplex scans, venograms, and intravascular ultrasound. May-Thurner syndrome was revealed in the left common iliac vein, prompting the deployment of an 18 mm × 16 mm stent. Subsequently, during a venogram, what initially appeared to be a vasospasm in the left common femoral vein was diagnosed as extrinsic iatrogenic venous compression due to acetabular hip screws. This was found after two IV injections of 400 mg nitrogen and one balloon angioplasty could not resolve the compression. After advancement over a 0.35" microwire and accurate positioning over the center of the left common femoral vein lesion, a 16 mm × 90 mm stent was deployed. The venogram and intravascular ultrasound also showed a similar compression in the right common femoral vein. Another 400 mg IV nitrogen did not expand the lesion, so it was concluded that there was similarly an iatrogenic venous compression of the right common femoral vein, also due to acetabular hip screws in the right femur. A follow-up was scheduled a couple of weeks later to address the issue in the right common femoral vein. The underreported issue of iatrogenic venous compression following joint replacements highlights the need for better recognition and management of vascular complications due to inflammation and intimal proliferation. This is especially the case in high-risk patients, such as those with May-Thurner syndrome.

Barriers to healthcare access and experiences of stigma: Findings from a coproduced Long Covid case-finding study.

BACKGROUND AND AIM: Long Covid is often stigmatised, particularly in people who are disadvantaged within society. This may prevent them from seeking help and could lead to widening health inequalities. This coproduced study with a Community Advisory Board (CAB) of people with Long Covid aimed to understand healthcare and wider barriers and stigma experienced by people with probable Long Covid. METHODS: An active case finding approach was employed to find adults with probable, but not yet clinically diagnosed, Long Covid in two localities in London (Camden and Merton) and Derbyshire, England. Interviews explored the barriers to care and the stigma faced by participants and were analysed thematically. This study forms part of the STIMULATE-ICP Collaboration. FINDINGS: Twenty-three interviews were completed. Participants reported limited awareness of what Long Covid is and the available pathways to management. There was considerable self-doubt among participants, sometimes reinforced by interactions with healthcare professionals (HCPs). Participants questioned their deservedness in seeking healthcare support for their symptoms. Hesitancy to engage with healthcare services was motivated by fear of needing more investigation and concerns regarding judgement about the ability to carry out caregiving responsibilities. It was also motivated by the complexity of the clinical presentation and fear of all symptoms being attributed to poor mental health. Participants also reported trying to avoid overburdening the health system. These difficulties were compounded by experiences of stigma and discrimination. The emerging themes reaffirmed a framework of epistemic injustice in relation to Long Covid, where creating, interpreting and conveying knowledge has varied credibility based on the teller's identity characteristics and/or the level of their interpretive resources. CONCLUSION: We have codeveloped recommendations based on the findings. These include early signposting to services, dedicating protected time to listening to people with Long Covid, providing a holistic approach in care pathways, and working to mitigate stigma. Regardless of the diagnosis, people experiencing new symptoms must be encouraged to seek timely medical help. Clear public health messaging is needed among communities already disadvantaged by epistemic injustice to raise awareness of Long Covid, and to share stories that encourage seeking care and to illustrate the adverse effects of stigma. PATIENT OR PUBLIC CONTRIBUTION: This study was coproduced with a CAB made up of 23 members including HCPs, people with lived experience of Long Covid and other stakeholders.

Plant extract preparation and green synthesis of silver nanoparticles using Swertia chirata: Characterization and antimicrobial activity against selected human pathogens.

Herbal medicinal plants have been used for centuries in traditional medicine, and it is interesting to see how modern research has identified the active compounds responsible for their therapeutic effects. The green synthesis of silver nanoparticles using herbal medicinal plants, such as Swertia chirata, is particularly noteworthy due to its antimicrobial properties. In the current study, the Swertia chirata plant was collected for the first time from the region of Murree, Punjab, Pakistan. After collection, extracts were prepared in different solvents (ethanol, methanol, chloroform, and distilled water), and silver nanoparticles were synthesized by reducing silver nitrate (AgNO3). The UV-visible spectrophotometer, SEM, and EDX were used to characterize the synthesized nanoparticles in terms of their size and shape. The phytochemical analysis of crude extract was performed to determine the presence of different kinds of phytochemicals. The antibacterial activity of plant extracts and the silver nanoparticles were then assessed using the agar well diffusion method against various pathogenic bacteria. The results showed that the plant contains several phytochemicals with remarkable antioxidant potential. The antibacterial analysis revealed that silver nanoparticles and the plant extracts exhibited a significant zone of inhibition against human pathogenic bacteria (Escherichia coli, S. capitis, B. subtilis, and Pseudomonas aeruginosa) as compared to the cefixime and norfloxacin. This implies that the nanoparticles have the potential to be used in nano-medicine applications, such as drug delivery systems, as well as for their antibacterial, antifungal, and antiviral activities. Additionally, the development and application of materials and technologies at the nanometer scale opens possibilities for the creation of novel drugs and therapies. Overall, the study highlights the promising potential of herbal medicinal plants found in Murree, Punjab, Pakistan, and green-synthesized silver nanoparticles in various fields of medicine and nanotechnology.

Exploring the lead-free halide Cs2MGaBr6 (M = Li, Na) double perovskites for sustainable energy applications.

In recent years, there has been a growing emphasis on the exploration of sustainable and eco-friendly materials well-suited for advanced applications in the realms of thermoelectrics and optoelectronics. Lead-free halide double perovskites have emerged as a compelling class of materials in this context. Nevertheless, despite their potential utility, thorough investigations into their thermal transport characteristics remain limited. In this systematic investigation, we employ density functional theory (DFT) and post-DFT techniques to elucidate the essential stability parameters, transport properties, and carrier-lattice interactions of the metal halide-based Cs2MGaBr6 (X = Li, Ga) double perovskites. Our assessment of structural stability involves a meticulous description of stability index parameters and the optimization of pristine structures using the GGA-PBE potential. Additionally, we calibrate the electronic structure while taking spin-orbit coupling (SOC) effects into consideration by using a combination of GGA and GGA + mBJ potentials. Our findings reveal that the TB-mBJ derived band gaps of 1.82 eV and 1.78 eV for Cs2LiGaBr6 and Cs2NaGaBr6 reside within the visible spectrum, prompting further investigation into their thermal transport characteristics. Moreover, we analyze the phonon characteristics and vibrational modes, extending our investigation to examine the electron-phonon coupling strength. The scrutiny of the Fröhlich coupling constant and the Feynman polaron radius unveils a stronger electron-phonon coupling strength. In the domain of thermoelectrics, the significant figure of merit (zT) values of 1.08 and 1.04 for Cs2LiGaBr6 and Cs2NaGaBr6, respectively, emphasize the considerable potential of these materials for deployment in renewable energy applications. Furthermore, our computational investigation into optical properties, including the dielectric constant, optical absorption, and refractive index, demonstrates optimal performance within the visible spectrum. Specifically, elevated absorption coefficient values of 30 × 10 4 cm - 1 for Cs2LiGaBr6 and 40 × 10 4 cm - 1 for Cs2NaGaBr6 are noted across visible and infrared spectra, highlighting their promising potential in optoelectronic and solar cell technologies.

High-precision characterization of quantum-cascade laser frequency response using wavelength modulation spectroscopy.

This paper investigates the impact of the quantum cascade laser's frequency modulation response on its tuning rate and tunability. We show a significant disparity in laser tuning rates and tunability between single and dual-frequency modulation schemes frequently used in typical direct absorption and wavelength modulation spectroscopy (WMS) techniques. We show that the DC-characterized tuning rate of a laser can be reduced significantly under a specific set of modulation frequencies of the laser injection current. We characterize these effects by simultaneous measurements of higher harmonic WMS of methane and nitrous oxide in the 7.8 µm spectral regions. We further show that WMS signal modulation broadening mechanisms and spectral structure, i.e., its zero-crossings and turning points, can be used to quantify such laser-modulation effects and validate laser frequency response under dual modulation schemes.

Adaptive responses of nitric oxide (NO) and its intricate dialogue with phytohormones during salinity stress.

Nitric oxide (NO) is a gaseous free radical that acts as a messenger for various plant phenomena corresponding to photomorphogenesis, fertilisation, flowering, germination, growth, and productivity. Recent developments have suggested the critical role of NO in inducing adaptive responses in plants during salinity. NO minimises salinity-induced photosynthetic damage and improves plant-water relation, nutrient uptake, stomatal conductance, electron transport, and ROS and antioxidant metabolism. NO contributes active participation in ABA-mediated stomatal regulation. Similar crosstalk of NO with other phytohormones such as auxins (IAAs), gibberellins (GAs), cytokinins (CKs), ethylene (ET), salicylic acid (SA), strigolactones (SLs), and brassinosteroids (BRs) were also observed. Additionally, we discuss NO interaction with other gaseous signalling molecules such as reactive oxygen species (ROS) and reactive sulphur species (RSS). Conclusively, the present review traces critical events in NO-induced morpho-physiological adjustments under salt stress and discusses how such modulations upgrade plant resilience.

Performance of Fourier-based activation function in physics-informed neural networks for patient-specific cardiovascular flows.

BACKGROUND AND OBJECTIVES: Physics-informed neural networks (PINNs) can be used to inversely model complex physical systems by encoding the governing partial differential equations and training data into the neural network. However, neural networks are known to be biased towards learning less complex functions, called spectral bias. This has important implications in modeling cardiovascular flows, where spatial frequencies can vary substantially across anatomies and pathologies (e.g., aneurysms or stenoses). Recent evidence suggests that Fourier-based activation functions have desirable properties, and can potentially reduce spectral bias; however, the performance and adequacy of such Fourier activation functions have not yet been evaluated in patient-specific cardiovascular flow applications. METHODS: The performance of sine activation function was evaluated against tanh and swish activation functions in a 1D advection-diffusion problem, an eccentric 2D stenosis model (Re=5000), and a patient-specific 3D aortic model (Re=823) under pulsatile flow conditions. CFD simulations were performed at high spatio-temporal resolution and data points were extracted for training the neural network. The number of training data points were normalized by L/D. The performance of the PINNs framework was evaluated with increasing number of training data points and across all three activation functions. RESULTS: Our results demonstrate that sine activation function presents desirable characteristics, such as monotonic reduction in errors, relatively faster convergence, and accurate eigen spectra at higher modes, compared to tanh and swish activation functions. Interestingly, for all activation functions, the domain-averaged errors tended to asymptote at ≈15-20% despite substantial increase in training point density. For 2D eccentric stenosis, errors asymptoted at a sensor point density of 40L/D. For 3D patient-specific aorta, this asymptote was achieved at 180L/D for all three activation functions with an error of ≈15% although sine activation function demonstrated relatively faster convergence. CONCLUSIONS: We have demonstrated that Fourier-based activation functions have higher performance in terms of accuracy and convergence properties for cardiovascular flow applications; however, inherent challenges of neural networks (e.g., spectral bias) can limit the accuracy to ≈15% under physiological, 3D patient-specific blood flow conditions.

Texture Estimation for Abnormal Tissue Segmentation in Brain MRI.

This chapter discusses multifractal texture estimation and characterization of brain lesions (necrosis, edema, enhanced tumor, nonenhanced tumor, etc.) in magnetic resonance (MR) images. This work formulates the complex texture of tumor in MR images using a stochastic model known as multifractional Brownian motion (mBm). Mathematical derivations of the mBm model and corresponding algorithm to extract the spatially varying multifractal texture feature are discussed. Extracted multifractal texture feature is fused with other effective features to enhance the tissue characteristics. Segmentation of the tissues is performed using a feature-based classification method. The efficacy of the mBm texture feature in segmenting different abnormal tissues is demonstrated using a large-scale publicly available clinical dataset. Experimental results and performance of the methods confirm the efficacy of the proposed technique in an automatic segmentation of abnormal tissues in multimodal (T1, T2, Flair, and T1contrast) brain MRIs.

Investigation of surface hardness, thermostability, tribo-corrosion, and microstructural morphological properties of microwave-synthesized high entropy alloy FeCoNiMnCu coating claddings on steel.

Deposition of high entropy alloy FeCoNiMnCu on SS-304 was carried out by microwave energy for application in "solid oxide fuel-cell (SOFC) interconnects". The ball-milling has been performed by taking "Fe, Co, Ni, Mn, and Cu" in equal 20 wt. % of before deposited on SS-304 substrate. The deposited steel with 20% Fe 20% Co 20% Ni 20% Mn 20% Cu high entropy alloy (HEA) was exposed to thermal-exposure in the air for up to 10 weeks at 800 °C. The uniform cladding distribution of 20% Fe 20% Co 20% Ni 20% Mn 20% Cu HEA particles can be apparently observed on SS-304 substrate by utilizing Scanning Electron Microscope (SEM), and Optical microscopy analysis. Homogeneity in the interfacial layer was evident by employing Scanning Electron Microscope (SEM) characterization. Results have indicated that after the thermal exposure of deposited steel with 20% Fe 20% Co 20% Ni 20% Mn 20% Cu in the air for up to ten weeks at 800 °C, a "protective Cr2O3 layer", and "high-entropy spinel coating" of (Fe, Co, Ni, Mn, Cu)3O4 have been formed. During microwave cladding, the emergence of harder-phases has contributed to the raised hardness. The wear behavior after coating of 20% Fe 20% Co 20% Ni 20% Mn 20% Cu HEA on SS-304 substrate has significantly enhanced due to the strengthened wear resistance and hardness of the coatings. Findings have exhibited that the formation of (Fe, Co, Ni, Mn, Cu)3O4 phase is a potential coating material for "SOFC interconnects" applications. Moreover, the cladding of SS304 with a composition of 20% Fe, 20% Co, 20% Ni, 20% Mn, and 20% Cu has demonstrated remarkable stability under thermal expansion studies. As the findings have revealed that the composite cladding has efficiently withstand significant variations in volume when subjected to elevated temperatures for a prolonged period of time, thus, exhibiting its superior thermal stability for SOFC-interconnect applications. Furthermore, the SEM images of the cladding surface, surface hardness, and tribocorrosion behavior of the coated material have been observed to identify the 20% Fe 20% Co 20% Ni 20% Mn 20% Cu HEA coating effect on SS-304 steel-substrate.

Structural, thermodynamic, and magnetic properties of SrFe12O19 hexaferrite modified by co-substitution of Cu and Gd.

A hard magnetic system of SrFe12O19 nanomaterial was modified according to the composition of Sr0.95Gd0.05Fe12-xCuxO19 with x = 0.0, 0.30, and 0.60 using the sol-gel technique. The structures of the samples were evaluated using X-ray diffraction (XRD) along with Rietveld refinement, and an M-type hexaferrite with a hexagonal structure was confirmed with a trace amount of the α-Fe2O3 phase. In addition, transmission electron microscopy (TEM) analysis revealed polycrystalline nanoplates in all samples. Furthermore, the bond structures of the octahedral and tetrahedral sites along with the thermodynamic properties of these ferrites were extracted from the FTIR spectra at room temperature. The Debye temperature (θD) decreased from 755.9 K to 749.3 K due to the co-substitution of Gd3+ at Sr2+ and Cu2+ at Fe3+. The magnetic hysteresis (M-H) measurements revealed that the coercivity decreased from 5.3 kOe to 1.5 kOe along with the highest magnetization saturation (Ms) of 65.2 emu g-1 for the composition Sr0.95Gd0.05Fe11.7Cu0.3O19, which is suitable for industrial application. The effect of local crystalline anisotropy in magnetization was explored using the law of approach to saturation (LAS). Finally, thermo-magnetization was recorded in the range from 400 K to 5 K for cooling under zero field and in the presence of a 100 Oe field, and magnetic transitions were tracked due to the introduction of the foreign atoms of Gd and Cu into SrFe12O19.