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High-power PEMFC performance requires holistic consideration of activation, ohmic, and concentration losses. A scalable production method of ORR electrocatalysts is developed to tackle all the critical factors to achieve practical PEMFC operation.

Chromism from phosphomolybdate – malachite green dye moiety through hydrogen bonding interaction with water molecules is reported. Interestingly, the substance with bound di-nitrogen or di-oxygen together with water molecules also exhibits color change. N2 or O2 binding vis-a-vis chromism is a new insight.

Coronary Artery Disease (CAD) is a cardiovascular disease that has the highest mortality rate. The non-invasive method for diagnosing CAD is coronary angiography which is expensive and exposes the patient to radiation. The present scenario for diagnosing CAD has motivated researchers to analyze and diagnose the disease using Machine Learning (ML) algorithms. In this work, the efficacy of various ML algorithms used to diagnose CAD disease is presented and compared. The proposed methodology aims to train the dataset using algorithms namely: K-Nearest Neighbor, Support Vector Machine, Logistic Regression, Naive Bayes, Decision Tree, Extreme Gradient Boosting, Random Forest, Extra Tree Classifier, and Light Gradient Boosting machine, to achieve accuracy for diagnosing the CAD. The experimental results are validated in the simulation environment, and the conclusions were drawn from the performance indices, i.e., Accuracy, Sensitivity, Specificity, Precision, F1-Score, and Binary cross-entropy cost function. The meta-analysis shows that Light Gradient Machine achieves an accuracy of 93.36%, which is the highest among other ML algorithms.

In this work, performance of four supervised machine learning algorithms namely: Multi Class Support Vector Machine (MC-SVM), K-Nearest Neighbor (KNN), Naive Bayes (NB), and Random Forest (RF) have been evaluated for the seizure classification when patient dataset is large. The named algorithms have been used to classify the epileptic seizures into: normal seizure, partial seizures, and generalized seizure. The classification is performed on the dataset of 26,28,33 and 40 patients. The algorithms were implemented in MATLAB® R2019a software tool. Using confusion matrix the performance metrics (i.e., accuracy, precision, sensitivity and specificity) have been calculated. It is observed that the performance of the RF algorithm is best among other algorithms, when applied to the large patient datasets. For 40 patient data, the RF algorithm gives accuracy, precision, sensitivity, and specificity as 98.01 %, 95.92 %, 95.52 %, and 98.75 %, respectively, which is highest among the named algorithms.

The reversible and cooperative activation process, which includes electron transfer from surrounding redox mediators, the reversible valence change of cofactors and macroscopic functional/structural change, is one of the most important characteristics of biological enzymes, and has frequently been used in the design of homogeneous catalysts. However, there are virtually no reports on industrially important heterogeneous catalysts with these enzyme-like characteristics. Here, we report on the design and synthesis of highly active TiO2 photocatalysts incorporating site-specific single copper atoms (Cu/TiO2) that exhibit a reversible and cooperative photoactivation process. Our atomic-level design and synthetic strategy provide a platform that facilitates valence control of co-catalyst copper atoms, reversible modulation of the macroscopic optoelectronic properties of TiO2 and enhancement of photocatalytic hydrogen generation activity, extending the boundaries of conventional heterogeneous catalysts. Reversible and cooperative activation processes are important characteristics of biological enzymes and can be used in designing catalysts. Highly active TiO2 photocatalysts incorporated with site-specific single copper atoms are now shown to exhibit such a photoactivation process.

We report a facile two-step method to synthesize nanostructured P2-Na2/3MnO2via ligand exchange and intercalation of sodium ions into ultrathin manganese oxide nanoplates. Sodium storage performance of the synthesized material shows a high capacity (170 mA h g−1) and an excellent rate performance.

Active Sn(0) particles are synthesized in high yields by the chemical reduction of the blue–black stannous oxide using freshly prepared sodium stannite solution as reducing agent at 40 °C and 60 °C. The Sn(0) particles are characterized using powder XRD, SEM, and DSC. The as-synthesized Sn(0) particles are applied as reagent for the regioselective synthesis of homopropargyl alcohols from propargyl bromide and aldehydes in distilled water at room temperature (in 50%–84% yields). No assistance of heat, microwave, ultrasound, organic co-solvent, co-reagent, or inert atmosphere is required for this reaction. The propargylation reaction is highly chemoselective towards aldehyde over other less electrophilic carbonyl functional groups such as ketone, amide, and carboxylic acid. Our in-house synthesized homopropargyl alcohols can be used to synthesize conjugated 1,3-diynes.

Epileptic seizure is a chronic and non-communicable disease which occurs in people of all ages. In the detection of epileptic seizures, electroencephalography (EEG) plays a vital role. Due to advantages like low cost, portability, etc., EEG is preferred over other brain acquisition techniques. To analyze EEG data with the increased number of segments, it will take additional time for the neurophysician to classify the seizures. To reduce the time in analyzing EEG data, two deep neural network-based models are proposed. In this paper, one model using the “long short-term memory (LSTM) model” and another using “bi-directional long short-term memory (Bi-LSTM)” are anticipated to classify whether the given data is normal or partial seizures or generalized seizure data. The EEG data of 40 patients is collected, and each patient’s data is split into 10-second segments. The algorithm is written in MATLAB® by giving the 10-second segments of all patients. The training is done on the personal computer with an improved system configuration which reduces training time from days to a few hours. The training time to train the network with the LSTM model is 82 min, and the network with Bi-LSTM model is 122 min. The accuracy achieved with LSTM and Bi-LSTM model is 90.89% and 90.92%, respectively.

Compared to nanostructured platinum (Pt) catalysts, ordered Pt-based intermetallic nanoparticles supported on a carbon substrate exhibit much enhanced catalytic performance, especially in fuel cell electrocatalysis. However, direct synthesis of homogeneous intermetallic alloy nanocatalysts on carbonaceous supports with high loading is still challenging. Herein, we report a novel synthetic strategy to directly produce highly dispersed MPt alloy nanoparticles (M = Fe, Co, or Ni) on various carbon supports with high catalyst loading. Importantly, a unique bimetallic compound, composed of [M(bpy)

Accurate estimation of crop yield is a challenging field of work. The hardware and software platform to predict the crop yield depends upon various factors like environment, soil fertility, genotype, and various interacting dependents. The task is complex owing to the data that needs to be collected in volumes to understand crop yield through wireless sensor networks and remote sensing. This paper reviews the past 15 years of research work in the development of estimating crop yield using deep learning algorithms. The significance of discussing advancements using deep learning techniques will help in decision making for predicting the crop yield. The hybrid combination of deep learning with remote sensing and wireless sensor networks can provide precision agriculture in the future.

Yellow ammonium phosphomolybdate (YAPM), a waste product of all under graduate (UG) chemistry laboratory classes, has been proved to be an efficient adsorbent for environmental application as a cationic ion exchanger. The water insoluble YAPM selectively removes cationic dye molecules from dye contaminated wastewater. Consequently, dye infested YAPM solid is produced with fascinating color but bears altered band gap energy. Dye contaminated yellow APM is regenerated in air oven from the dye infested YAPM solid powder by heat treatment at ~ 300 °C and reused with full potential. So it becomes a solid phase extractant. Robust yellow APM turns to green APM (GAPM) upon UV light exposure because of the hoarded electrons in the basket like Keggin structure of phosphomolybdate (PMo12O40−3) moiety, and thereby the dye exchange capability is improved, admirably. Thus, the remediation of dye contaminated wastewater by YAPM has been found to be fruitful by YAPM and more potential dye remediation by GAPM.

A highly active and stable non-Pt electrocatalyst for hydrogen production has been pursued for a long time as an inexpensive alternative to Pt-based catalysts. Herein, we report a simple and effective approach to prepare high-performance iron phosphide (FeP) nanoparticle electrocatalysts using iron oxide nanoparticles as a precursor. A single-step heating procedure of polydopamine-coated iron oxide nanoparticles leads to both carbonization of polydopamine coating to the carbon shell and phosphidation of iron oxide to FeP, simultaneously. Carbon-shell-coated FeP nanoparticles show a low overpotential of 71 mV at 10 mA cm–2, which is comparable to that of a commercial Pt catalyst, and remarkable long-term durability under acidic conditions for up to 10 000 cycles with negligible activity loss. The effect of carbon shell protection was investigated both theoretically and experimentally. A density functional theory reveals that deterioration of catalytic activity of FeP is caused by surface oxidation. Extende...

The main aim of this tutorial is to apprise readers about parameter extraction and bias-point calculation using Enz–Krummenacher–Vittoz compact metal oxide semiconductor (MOS) model equation. The model equation has been applied to an NMOS (N-channel metal oxide semiconductor) transistor case present on the P-substrate and P-well. Two cases are considered to show parameters extraction and bias-point calculation for a modified/unmodified value of the transistor threshold voltage. After presenting equation simplification for the two cases, different parameter extraction methods are discussed. Then a common drain configuration biased by a resistance is simulated to match by hand-calculated results.

Objectives: This present study was to evaluate the clinical profile of patients with amblyopia. Methods: A detail history, clinical examinations and relevant investigations were performed to all cases of amblyopia. Cycloplegic refraction under atropine sulphate 1 % eye ointment for 5-10 years and eye drop homatropine 2 % for 11-20 years age group was performed. Management material was tissue paper and micropore tape for patching. It was done in the form of 3 hours or 6 hours patching. Visual improvement tested every month upto 3 months and then after 3 months by Snellen’s distant visual acuity or Landolt C chart. Results: Data was analyzed by using simple statistics methods with the help of MS-Office software. Conclusions: Amblyopia was commonly seen in children. Anisometropic amblyopia was very common. Refractive error was commonly seen in cases with hypermetropia with astigmatism, myopia with astigmatism and hypermetropia. Majorities of these cases had 2-4D and 4.25-6D refractive error differences and had 6/24-6/12 visual acuity.Alternate divergent and unilateral partially accommodative convergent were the most common type of squint seen. Majorities of cases with anisometropic amblyopia had seen >2 snellen’s line improvement of visual acuity in 3 hours patching regimens. Hence, early intervention is ideal, with appropriate management and treatment amblyopia patients are likely obtain a successful outcome, and possibly full resolution. Key words: Children, amblyopia, refractive error, visual acuity

We report a facile two-step method to synthesize nanostructured P2-Na2/3MnO2via ligand exchange and intercalation of sodium ions into ultrathin manganese oxide nanoplates. Sodium storage performance of the synthesized material shows a high capacity (170 mA h g-1) and an excellent rate performance.

We report a new synthesis method to grow Zn-doped CuS (CZS) nanoballs on multi-walled carbon nanotube (MWCNT) surfaces from a single molecular source [Cu(en) 2 ZnCl 4 ]·DMSO complex. The single precursor acts as the source for both Cu + 2 and Zn + 2 ions for the formation of nanocrystalline balls. High resolution electron micrographs clearly revealed the formation of crystalline CZS nanoballs on the surface of MWCNT. The chemical composition and local bonding of CZS have been examined by XPS and UPS analysis. A current-voltage (I-V) characteristic on single CZS nanoballs was carried out using conducting probe atomic force microscopy (C-AFM). A clear hysteresis in I-V characteristics demonstrated the bipolar resistive switching in the nanoballs anchored with MWCNTs at low set and reset voltages. The study reveals a novel technique to grow doped semiconductor nanocrystal for its application in resistive switching memory devices.

Various kinds of nanostructured materials have been extensively investigated as lithium ion battery electrode materials derived from their numerous advantageous features including enhanced energy and power density and cyclability. However, little is known about the microscopic origin of how nanostructures can enhance lithium storage performance. Herein, we identify the microscopic origin of enhanced lithium storage in anatase TiO2 nanostructure and report a reversible and stable route to achieve enhanced lithium storage capacity in anatase TiO2. We designed hollow anatase TiO2 nanostructures composed of interconnected ∼5 nm sized nanocrystals, which can individually reach the theoretical lithium storage limit and maintain a stable capacity during prolonged cycling (i.e., 330 mAh g-1 for the initial cycle and 228 mAh g-1 for the 100th cycle, at 0.1 A g-1). In situ characterization by X-ray diffraction and X-ray absorption spectroscopy shows that enhanced lithium storage into the anatase TiO2 nanocrystal results from the insertion reaction, which expands the crystal lattice during the sequential phase transition (anatase TiO2 → Li0.55TiO2 → LiTiO2). In addition to the pseudocapacitive charge storage of nanostructures, our approach extends the utilization of nanostructured TiO2 for significantly stabilizing excess lithium storage in crystal structures for long-term cycling, which can be readily applied to other lithium storage materials.

A low-temperature, wet-chemical process for the synthesis of single wall carbon nanotubes (SWCNTs) films on large area, transparent, flexible substrates were developed and its application to ammonia detection at room temperature were demonstrated. The carboxyl groups were attached in the sidewalls of carbon nanotubes due to wet-chemical process which helps to improve the sensor performance. The transmittance measurement showed that the film is ninety percent transparent to visible spectrum with respect to air. Selectivity measurements were also performed. The sensor responses were same for both the fat and bend film. The present SWCNTs based sensors could potentially be used to develop low cost, flexible, foldable and disposable sensor system for the monitoring of toxic gases like ammonia in environment.

Arsenic detection, far below the WHO's permissible limit, is reported using SERS studies. A stable deliverable FeOOH doped dendritic nanostructured Ag surface, obtained from a chosen galvanic reaction under ice cold conditions, serves well as a SERS substrate, which affirms affinity based arsenic detection down to ∼10−10 M level.

High purity Sn(0) has been obtained as a result of reduction of SnO by sodium stannite (Na2SnO2) in aqueous solution. The process stands unique for the production of tin metal. The as-synthesized tin finds applications in synthetic organic chemistry as a reagent for the allylation of aldehydes and ketones in distilled water at room temperature to give rise to the corresponding homoallylic alcohols with high yield. The reaction occurs without the assistance of heat, ultrasonic vibration, co-solvents/co-reagents, etc. Enhancement of the reaction rate of allylation was observed in water rather than THF. The manipulation of allylation reaction becomes easy with active tin material.

A vanadium complex, [(C5H5N)2V2O3·H2O], of different morphologies has been obtained via a modified hydrothermal procedure using pyridine and VOSO4 salt as the starting material. The evolved [(C5H5N)2V2O3·H2O] nanobelts are of 50–200 nm in width and of a length up to several millimeters. At higher temperatures (600 °C), the solid [(C5H5N)2V2O3·H2O] nanostructures are converted to vanadium pentoxide (V2O5) and vanadium dioxide (VO2) when heated in air and nitrogen atmosphere, respectively. During growth, the mechanism of the evolution of octahedra, truncated octahedra, and hollow truncated octahedra of [(C5H5N)2V2O3·H2O] are reported for the first time. These types of well-structured morphology are also isolated while V2O5 and VO2 are evolved. The as-grown belt-like and octahedral morphologies of [(C5H5N)2V2O3·H2O] are retained during the solid-state transformation, suggesting a route to evolve crystalline nanomaterials. Again, the morphological evolution of the [(C5H5N)2V2O3·H2O] nanostructures has been examined to be pyridine and precursor vanadyl sulfate (VS) concentration dependent. Thus, we are able to isolate truncated octahedra as an intermediate during the formation of [(C5H5N)2V2O3·H2O] nanobelts and nanoflowers with a high pyridine (Py) concentration. Interestingly, longer reaction times successively featured the transformation of truncated octahedra into nanobelts. Nanobelt evolution is not observed at low pyridine concentrations. However, the formation of octahedral morphology takes place at low pyridine concentration. All of the nanostructures were critically examined and characterized thoroughly by various physical techniques to ascertain their purity, structure and composition. An interesting, thermodynamically stable, single crystalline product from DMF soluble [(C5H5N)2V2O3·H2O] has been characterized, which indirectly supports the composition of [(C5H5N)2V2O3·H2O]. Selectively, vanadium pentoxide nanobelts have been found to be an efficient catalyst for the oxidative coupling of 2-naphthol to binaphthols under a molecular oxygen atmosphere.

This paper proposes a method of installing phasor measurement units (PMU) in multiple stages. The scheme is developed on the concept of bus tier system and provides an optimal number of PMUs with a strategy to install them in a particular stage. The synchronized phasor measurements from the PMUs placed by the proposed method are used in developing a hybrid state estimator (HSE). The HSE estimates the voltage phasor at all the buses of a power system with a limited numbers of PMUs in steady state as well as in the presence of disturbances even in that part of network which is unobservable through PMUs. Performance of the proposed phased installation scheme for HSE is evaluated on the number of standard test system and the simulation results shows an improvement in the accuracy of the estimated states as compared to the existing methods in the literature.

Electrochemistry is used in an aqueous allylation reaction using zinc chloride as the reagent. A unit galvanic cell using a beaker containing an aqueous zinc chloride solution, zinc rod, TCO glass plate and connecting copper wire has been designed. Instead of using a connecting copper wire, an external bias can be used for applying voltage from the outside. The zinc rod served as a self-decaying anode and the TCO glass substrate as the cathode. During the process, a wire-shaped nano zinc architecture was formed from zinc chloride on the cathode. Wire-shaped nano zinc is the active reagent for the allylation of aldehydes or imines. The corresponding homoallylic alcohols or amines are prepared in good yields. Both the zinc salts and water can be recycled.

Well-separated Si/ZnS radial nanowire heterojunction-based light-emitting devices have been fabricated on large-area substrates by depositing n-ZnS film on p-type nanoporous Si nanowire templates. Vertically oriented porous Si nanowires on p-Si substrates have been grown by metal-assisted chemical etching catalyzed using Au nanoparticles. Isolated Si nanowires with needle-shaped arrays have been made by KOH treatment before ZnS deposition. Electrically driven efficient white light emission from radial heterojunction arrays has been achieved under a low forward bias condition. The observed white light emission is attributed to blue and green emission from the defect-related radiative transition of ZnS and Si/ZnS interface, respectively, while the red arises from the porous surface of the Si nanowire core. The observed white light emission from the Si/ZnS nanowire heterojunction could open up the new possibility to integrate Si-based optical sources on a large scale.

In this paper, the design of electron gun for a 0.67 THz gyrotron is presented. The in-house code MIGSYN is used to estimate the initial gun parameters. The electron trajectory tracing 2.5-dimensional (2.5-D) code EGUN is used to optimize the electron gun design. The parametric analysis and misalignment study is also carried out to provide the flexibility in the actual fabrication of the device.

Nonferromagnetic ${\rm SnO}_{2}$ nanowires show ferromagnetism at room temperature, which is significantly enhanced upon irradiation by ultraviolet (UV) light of wavelength 365 nm. The structural characterizations on as-grown, UV-irradiated, and ${\rm O}_{2}$ -annealed samples show no measurable difference in X-ray diffraction profiles and field-emission scanning and transmission electron microscopy images. But optical absorption, photoluminescence, and X-ray photoelectron spectroscopy reveal a significant effect of UV irradiation and establish a remarkable enhancement of O vacancies in ${\rm SnO}_{2}$ nanowires upon UV light irradiation, which diminishes after annealing in the presence of ${\rm O}_{2}$ gas. The as-grown and ${\rm O}_{2}$ -annealed nanowires show weak ferromagnetism at room temperature, but the UV-irradiated nanowires show strong ferromagnetism. The origin of such ferromagnetism in pure (undoped) ${\rm SnO}_{2}$ is attributed to the presence of oxygen vacancies, which is tunable externally using UV irradiation.

Tuning of the tin oxide (SnO/SnO2) heterojunction (TOHJ) has been made possible by heating the as-prepared p-type SnO semiconductor in air in a controlled fashion. Thus a better photocatalytic activity for dye degradation under UV, visible as well as solar light irradiation was achieved. Multiple reflection of light and the TOHJ of SnO plates facilitate the photocatalysis reactions.