Retrieval of parameters in micromixer with obstacle by cascade-forward-type artificial neural network: Comparison of four training algorithms under noisy data

Two parameters are retrieved in a passive Y-type micromixer with circular obstacle by cascade-forward-type artificial neural network (CFANN). The governing equations are solved by the finite volume method, under specific boundary conditions. The numerical model is then used to compute velocity profile and mixing efficiency, for different values of the Reynolds number. Thus, the velocity profiles along with Reynolds number (Re) and mixing efficiency (η) constitute the input–output pair of data. These data are used to train CFANN, and the network is monitored through different means, like, histograms, performance curves, and so forth. For inverse analysis, the trained CFANN model is fed with a new velocity profile as input, and corresponding values of Reynolds number and mixing efficiency are obtained as output. In an attempt to construct the optimum CFANN model, various combinations were explored, like, (1) different numbers of neurons in the hidden layer, (2) different noise levels in input data, and (3) different algorithms in the training stage. Finally, the CFANN with 10 hidden layer neurons with Levenberg–Marquardt (LM) algorithm was found to give retrieved values with up to 0.96% absolute error for all levels of noise in the input data. Also, the CFANN model with the LM algorithm has a very high value of regression coefficient of greater than 0.998, under all the noise values. Scaled conjugate gradient algorithm gives good results for the no-noise case, but fails poorly with the rise of noise. Other algorithms, like, Bayesian regularization and resilient backpropagation, perform poorly even in the no-noise case. The present approach is highly simple, accurate, and time efficient for applying inverse analysis in micromixers.     

Performance evaluation of 67 denoising filters in ultrasound images: A systematic comparison analysis

Noise corrupts ultrasound images and degrades spatial and contrast resolutions. Hence, it is challenging to characterize the lesions precisely using ultrasound images. The present study aims to evaluate 67 denoising filters and select the best one for ultrasound image denoising. Seven test images were synthesized to evaluate the performance of filters at three different noise levels. Eleven full-reference quantitative image quality metrics (IQMs) were employed to evaluate the performance of the filters. A new filter evaluation method, Rank Analysis, was introduced and utilized at each noise level. The ten best filters with the smallest mean rank in all noise levels were defined for further analysis on real ultrasound images. The Rank Analysis was also employed for real ultrasound images, and filters were evaluated based on 14 IQMs (11 full-reference and three no-reference). Finally, the best filter was defined using the repeated measures analysis statistical test. According to the Rank Analysis results, the Spatial correlation (SCorr) filter obtained the best results with the mean rank scores±SD of 1 ± 0, which was significantly better than the other nine filters (p < 0.001). The second-best results were achieved by three filters, Bitonic, most homogeneous neighborhood, and Lee diffusion (p < 0.05). We concluded that SCorr is the best filter for ultrasound image denoising. It can be used in the pre-processing step before segmentation and diagnostic procedures. In addition, a new filter evaluation method, Rank Analysis, was introduced in this study, which is easy to use, fast, and provides reliable results. So, it can be used to evaluate newly developed filters in the future studies.     

Stratum-Confined Solid-State Reaction (SC-SSR) toward Colloidal Silicon-Based Hollow Nanostructures for Bioapplications

Silicon nanostructures (SiNSs) can provide multifaceted bioapplications; but preserving their subhundred nm size during high-temperature silica-to-silicon conversion is the major bottleneck. The SC-SSR utilizes an interior metal-silicide stratum space at a predetermined radial distance inside silica nanosphere to guide the magnesiothermic reduction reaction (MTR)-mediated synthesis of hollow and porous SiNSs. In depth mechanistic study explores solid-to-hollow transformation encompassing predefined radial boundary through the participation of metal-silicide species directing the in-situ formed Si-phase accumulation within the narrow stratum. Evolving thin-porous Si-shell remains well protected by the in-situ segregated MgO emerging as a protective cast against the heat-induced deformation and interparticle sintering. Retrieved hydrophilic SiNSs (<100 nm) can be conveniently processed in different biomedia as colloidal solutions and endocytosized inside cells as photoluminescence (PL)-based bioimaging probes. Inside the cell, rattle-like SiNSs encapsulated with Pd nanocrystals can function as biorthogonal nanoreactors to catalyze intracellular synthesis of probe molecules through C-C cross coupling reaction.     

Strain Anisotropy Driven Spontaneous Formation of Nanoscrolls from 2D Janus Layers

2D Janus transition metal dichalcogenides (TMDs) have attracted attention due to their emergent properties arising from broken mirror symmetry and self-driven polarization fields. While it has been proposed that their vdW superlattices hold the key to achieving superior properties in piezoelectricity and photovoltaic, available synthesis has ultimately limited their realization. Here, the first packed vdW nanoscrolls made from Janus TMDs through a simple one-drop solution technique are reported. The results, including ab initio simulations, show that the Bohr radius difference between the top sulfur and the bottom selenium atoms within Janus ${\mathrm{M}}_{\mathrm{Se}}^{\mathrm{S}}$ (M = Mo, W) results in a permanent compressive surface strain that acts as a nanoscroll formation catalyst after small liquid interaction. Unlike classical 2D layers, the surface strain in Janus TMDs can be engineered from compressive to tensile by placing larger Bohr radius atoms on top (${\mathrm{M}}_{\mathrm{S}}^{\mathrm{Se}})$to yield inverted C scrolls. Detailed microscopy studies offer the first insights into their morphology and readily formed Moiré lattices. In contrast, spectroscopy and FETs studies establish their excitonic and device properties and highlight significant differences compared to 2D flat Janus TMDs. These results introduce the first polar Janus TMD nanoscrolls and introduce inherent strain-driven scrolling dynamics as a catalyst to create superlattices.     

Severe hypertriglyceridemia in an infant on chronic hemodialysis

Severe hyperlipidemia is a risk factor for cardiovascular disease. Children with chronic kidney disease and end stage renal disease are at risk for development of hyperlipidemia. In this report, we describe a 7-month-old male infant with Denys–Drash syndrome who was found to have a “milky-layer” floating on the deaerator of the hemodialysis machine. Investigations showed severe hypertriglyceridemia of >1000 mg/dl. The patient had been on chronic continuous manual peritoneal dialysis until 6 months of age and recently had been switched to hemodialysis. Management included lowering of caloric intake and addition of medium chain triglyceride with reduction of the serum triglyceride levels to 300–400 mg/dl. Close monitoring of serum lipids and timely intervention is important to prevent serious complications associated with dyslipidemia. Observation of the “milky layer” in the deaerator of the hemodialysis machine may be an interesting visual clue of underlying severe hypertriglyceridemia.     

Strategies for Interference of Insulin Fibrillogenesis: Challenges and Advances

The discovery of insulin came with very high hopes for diabetic patients. In 2021, the world celebrated the 100th anniversary of the discovery of this vital hormone. However, external use of insulin is highly affected by its aggregating tendency that occurs during its manufacturing, transportation, and improper handling which ultimately leads to its pharmaceutically and biologically ineffective form. In this review, we aim to discuss the various approaches used for decelerating insulin aggregation which results in the enhancement of its overall structural stability and usage. The approaches that are discussed are broadly classified as either a measure through excipient additions or by intrinsic modifications in the insulin native structure.     

Machinability and surface morphology investigations of multiwall carbon nanotube reinforced aluminium 7075 metal matrix composite during electrical discharge machining: A grey relational approach

Multiwall carbon nanotube buttressed aluminium 7075 metal matrix composite was synthesized through an amended liquid metallurgy method, which consisted semisolid stirring, ultrasonic treatment and squeeze casting. Aim was to investigate its machinability and surface morphology during electrical discharge machining. Variable machining factors were peak current, pulse-on time and gap voltage, whereas the responses under investigation were electrode wear rate, material removal rate and average surface roughness. Results revealed electrode wear rate, material wear rate and average surface roughness increased on increasing peak current and pulse-on time, but all these responses behaved inversely with the increase of gap voltage. Average surface roughness reduced by around 44 % on reducing the peak current from 10 A to 4 A and increasing gap voltage from 55 V to 80 V at constant pulse-on time of 300 μs; however, it increased by around 25 % on reducing the gap voltage from 80 V to 55 V and increasing the pulse-on time from 100 μs to 300 μs at constant peak current of 10 A. Significance of the process parameters were verified, regression models were developed and morphology of the machined surfaces was studied. Finally, multiple response optimization was conducted following grey relational approach.     

A Novel TiO2–TiC–TiC0.3N0.7–C–SiCN Multiphase Ceramic Nanocomposite from Preceramic Polymer Pyrolysis

Journal of Inorganic and Organometallic Polymers and Materials - The current investigation describes the synthesis of SiTiCNO ceramics derived from the mixture of a preceramic polymer...     

Modelling and Optimization of Phase Locked Loop under Constrained Channel Length and Width of MOSFETs

Silicon - CMOS integrated circuits consisting of MOSFETs have tradeoffs among their performance parameters. Hence they need minimization in those tradeoffs calling for multi objective optimization...