Synthesis and characterization of nanosized titanium dioxide and silicon dioxide for corrosion resistance applications

We are reporting the preparation and characterization of nano-titanium dioxide and silica. The corrosion resistance performance of these nanopigments in silicone as well as silicone–polypyrrole Interpenetrating Polymer Network has been evaluated by impedance spectroscopy. The capacitance and resistance exerted by this nanocomposite coating were compared with the microcomposite coating and found that the nanocomposite coatings has the resistance in the order of 10⁸ Ω cm² in 3% sodium chloride solution, which is more than the microcomposite coating. The comparison of heat resistance performance of these composite coatings indicates that nanocomposite coatings exhibit higher heat resistance property than the microcomposite coatings.     

Impact of genotype,seasons and manufacturing process on the activities of peptidase and lipoxygenase in tea

Tea flush shoots comprising three leaves and a bud were harvested from five different cultivars planted in a single area of UPASI Tea Research Farm and analysed for lipoxygenase (LOX) and peptidase activities. Among the cultivars, UPASI-3 recorded high peptidase activity, while UPASI-9 registered significantly higher lipoxygenase activity. This study suggested the influence of genotype on these enzymes. Green leaves sampled during mid-April to May (Premonsoon) exhibited higher peptidase activities, while LOX activity was predominant during monsoon period (June to August). Peptidase activity was higher in actively growing tea tissues (bud) and decreased with shoot maturity, whereas LOX activity significantly increased with the maturity of shoot from bud to third leaf and rapid decline in the internodes. During manufacturing process, the activity of both the enzymes varied widely and maximum peptidase activity was observed in withered leaves and cut dhool had maximum LOX activity. The flavour analysis was carried out in green leaf, withered leaf, cut dhool, fermented dhool and black tea which indicated that the value of flavour index was higher in final black tea and lowest in green leaf. This provides significant information that most of the aroma compounds are formed during processing (after harvesting only).     

Characterization of Adrenal miRNA-Based Dysregulations in Cushing’s Syndrome

MiRNAs are important epigenetic players with tissue- and disease-specific effects. In this study, our aim was to investigate the putative differential expression of miRNAs in adrenal tissues from different forms of Cushing’s syndrome (CS). For this, miRNA-based next-generation sequencing was performed in adrenal tissues taken from patients with ACTH-independent cortisol-producing adrenocortical adenomas (CPA), from patients with ACTH-dependent pituitary Cushing’s disease (CD) after bilateral adrenalectomy, and from control subjects. A confirmatory QPCR was also performed in adrenals from patients with other CS subtypes, such as primary bilateral macronodular hyperplasia and ectopic CS. Sequencing revealed significant differences in the miRNA profiles of CD and CPA. QPCR revealed the upregulated expression of miR-1247-5p in CPA and PBMAH (log2 fold change > 2.5, p < 0.05). MiR-379-5p was found to be upregulated in PBMAH and CD (log2 fold change > 1.8, p < 0.05). Analyses of miR-1247-5p and miR-379-5p expression in the adrenals of mice which had been exposed to short-term ACTH stimulation showed no influence on the adrenal miRNA expression profiles. For miRNA-specific target prediction, RNA-seq data from the adrenals of CPA, PBMAH, and control samples were analyzed with different bioinformatic platforms. The analyses revealed that both miR-1247-5p and miR-379-5p target specific genes in the WNT signaling pathway. In conclusion, this study identified distinct adrenal miRNAs as being associated with CS subtypes.     

Reliable nonfragile tracking control for switched systems with external disturbances

With the assistance of reliable control technique, the nonfragile tracking problem has been proposed in this paper for a class of switched systems with external disturbances under the aegis of modified repetitive controller. Notably, the designed repetitive controller is used to improve the tracking performance of the addressed switched systems. Preciously, the influence of external disturbances are estimated through the improved equivalent-input-disturbance strategy, wherein the effect caused by the external disturbances to the output channel are reduced by the aid of modified repetitive control strategy. The fundamental intention of this control synthesis is that the output of the system precisely tracks the reference signal even in the presence of external disturbances and gain fluctuations. For that cause, Lyapunov stability technique in conjunction with average dwell time approach is implemented to obtain adequate conditions in the shape of linear matrix inequalities which insists the exponential stability for the addressed system. Ultimately, the efficiency and supremacy of the proposed control schemes are justified via two numerical examples, wherein it is exposed to view that the developed control strategy is capable of good tracking performance and also estimates the external disturbances efficiently.     

Intramuscular EMG classifier for detecting myopathy and neuropathy

This article presents an automatic diagnostic system to classify intramuscular electromyography (iEMG) signals, thereby detecting neuromuscular disorders. To this end, we tailored the center symmetric local binary pattern (CSLBP) to analyze one-dimensional ($1$-D) signals. In this approach, the $1$-D CSLBP feature extracted from a decimated iEMG signal is fed to a combination of classifiers, which in turn assigns a set of labels to the signal, and ultimately the signal category is determined by the Boyer-Moore majority voting (BMMV) algorithm. The proposed framework was investigated with a benchmark iEMG dataset that contains signals recorded from three different muscles: biceps brachii (BB), deltoideus (DE), and vastus medialis (VM). In a repeated $10$-fold cross-validation, CSLBP-Combined-Classifiers-BMMV (CSLBP-CC-BMMV) achieved an average classification accuracy of $92.80$%, $94.25$%, and $93.71$% for the iEMG signals recorded from BB, DE, and VM muscle, respectively. Interestingly, the performance of CSLBP-CC-BMMV surpassed the other published approaches and ensemble learning methods that are akin to our scheme in terms of classification accuracy and computational time.     

Effect of Silicon Segregation in the Argon Arc Welded Incoloy 20 Superalloy

Silicon - Incoloy 20 is prone to hot cracking due to micro-segregation of alloying elements. The aim of the work is to investigate the chances of curtailing the micro-segregation of elements using...     

Experimentation,simulation, and statistical analysis of nanofillers reinforced bio-based polyurethane foam for acoustical applications

This research aims to develop bio-based polyurethane foam (PU) with nanofillers to absorb sound energy across a broad frequency range and compare experimental results to those from simulation and optimization. PVDF (Polyvinylidene fluoride), MgO (Magnesium oxide), and Ni (Nickel) nanofillers were incorporated into bio-based PU through absorption and hydrothermal reduction technique, which includes mechanical stirring, compressing, heating, and evaporating. To determine the weight percentages of nanofillers, the design of the experimental approach was utilized. As per ASTM standard E 1050-12, the bio-based PU foam composite's sound absorption coefficient (SAC) was assessed using an impedance tube setup. Response Surface Methodology was utilized to estimate optimum sample weight percentages using a central composite design (CCD) with weight percentages of the three nanofillers as input and the noise reduction coefficient (NRC) as response output. According to the CCD results, the combination of 15 wt% PVDF, 10 wt% MgO, and 5 wt% Ni shows the highest NRC value of 0.66. Then, a confirmation sample was prepared, and the NRC was calculated. The NRC achieved for the confirmation sample was 0.62. SAC simulation results are contrasted with experimental data using COMSOL Multiphysics 5.5. The confirmation sample's average sound pressure level (SPL) reduction ranges from 2 to 29 dB, according to the SPL plot. The conclusion shows that bio-based composite foam may be an excellent material for absorbing sound in vehicles and aircraft and reducing industrial noise.     

Effect of storage time on the antimicrobial properties of chitosan

Chitosan (CS) is well known as one of the natural polymers. It is one of the familiar antibacterial materials owing to its safety, non-toxicity and biocompatibility. However, its prolonged capability to act as an antibacterial agent is not yet investigated in detail. i.e., as to how much time it can withstand its ability as an antibacterial agent is very significant for practical purposes. Hence, in the present study, CS solution and thin films in different ratios were prepared and were stored up to 24 months. Later observations were carried on different samples after storage time to assess its potential toward antimicrobial activity. It was noted that CS thin films had superior properties even after storage time of 24 months when compared to solution and powder forms. In addition to the above, morphology of the nanofilms and the presence of functional groups were also studied in detail.