Inderjeet Singh

A new approach for crystallization of copper( ii ) oxide hollow nanostructures with superior catalytic and magnetic response

We report the synthesis of copper(II) oxide hollow nanostructures at ambient pressure and close to room temperature by applying the soft templating effect provided by the confinement of droplets in miniemulsion systems. Particle growth can be explained by considering a mechanism that involves both diffusion and reaction control. The catalytic reduction of p-nitrophenol in aqueous media is used as a model reaction to prove the catalytic activity of the materials: the synthesized hollow structures show nearly 100 times higher rate constants than solid CuO microspheres. The kinetic behavior and the order of the reduction reaction change due to the increase of the surface area of the hollow structures. The synthesis also leads to modification of physical properties such as magnetism.

Anomalous magnetic behavior below 10 K in YCrO3 nanoparticles obtained under droplet confinement

Nanoparticles of multiferroic YCrO3 synthesized using the droplet confinement of miniemulsions show unusual features in the magnetic properties at low temperatures, which have not been reported before. Below 10 K, there is a sudden increase in the magnetization, and the nature of M–H hysteresis loops changes appreciably. The hysteresis loop shows two contributions, one similar to ferromagnetic and another similar to that expected from antiferromagnetic systems. This behavior can be understood by the formation of elongated grains or mesocrystals. It is remarkable that YCrO3 behaves quite differently from other multiferroic chromates such as ACrO3 (A = In, Sc, Sm).

Need for optimizing catalyst loading for achieving affordable microbial fuel cells

Microbial fuel cell (MFC) technology is a promising technology for electricity production together with simultaneous water treatment. Catalysts play an important role in deciding the MFC performance. In most reports, effect of catalyst - both type and quantity is not optimized. In this paper, synthesis of nanorods of MnO2-catalyst particles for application in Pt-free MFCs is reported. The effect of catalyst loading i.e., weight ratio, with respect to conducting element and binder has been optimized by employing large number of combinations. Using simple theoretical model, it is shown that too high (or low) concentration of catalysts result in loss of MFC performance. The operation of MFC has been investigated using domestic wastewater as source of bio-waste for obtaining real world situation. Maximum power density of ∼61 mW/m(2) was obtained when weight ratio of catalyst and conducting species was 1:1. Suitable reasons are given to explain the outcomes.

Evolution of hollow nanostructures in hybrid Ce1−x Cu x O2 under droplet confinement leading to synergetic effects on the physical properties

The paper discusses a successful strategy for tuning the hollow, porous or even solid morphologies of pure and Cu2+-doped CeO2 nanostructures. The reaction of nanodroplets at the interface in miniemulsions is significantly affected by the concentration of dopants. The growth mechanism is both reaction- as well as diffusion-controlled, which finally determines the particular morphology. With a varying degree of dopant concentration and quantum confinement, the concentration of Ce3+ available on the surface of the nano-droplets and -particles is found to change quite appreciably. This immediately leads to modulation in the physical properties, such as ferromagnetism or absorption. The significant red shift in the absorption spectra and associated broadband visible photoluminescence opens newer applications for the present material in visible optoelectronic devices.

Genetic Diversity in Gorkhas: an Autosomal STR Study.

Genotyping of highly polymorphic autosomal short tandem repeat (STR) markers is a potent tool for elucidating genetic diversity. In the present study, fifteen autosomal STR markers were analyzed in unrelated healthy male Gorkha individuals (n = 98) serving in the Indian Army by using AmpFlSTR Identifiler Plus PCR Amplification Kit. In total, 138 alleles were observed with corresponding allele frequencies ranging from 0.005 to 0.469. The studied loci were in Hardy-Weinberg Equilibrium (HWE). Heterozygosity ranged from 0.602 to 0.867. The most polymorphic locus was Fibrinogen Alpha (FGA) chain which was also the most discriminating locus as expected. Neighbor Joining (NJ) tree and principal component analysis (PCA) plot clustered the Gorkhas with those of Nepal and other Tibeto-Burman population while lowlander Indian population formed separate cluster substantiating the closeness of the Gorkhas with the Tibeto-Burman linguistic phyla. Furthermore, the dataset of STR markers obtained in the study presents a valuable information source of STR DNA profiles from personnel for usage in disaster victim identification in military exigencies and adds to the Indian database of military soldiers and military hospital repository.

Prediction of Fat Mass and Validation Using 3D-Whole Body Scanner in Healthy Indian Males

Background: BMI generally overestimates adiposity (i.e. body fat tissue) and underestimates excess body fat on those with less lean body mass. Aim: We wanted to assess the hypothesis that Fat Mass (FM) measured by bio impedance analysis (BIA) is comparable to the predicted Body Fat Mass (BFM) using 3D scanned anthropometric dimensions. Methods: The present paper investigates whether anthropometric measurements using 3D whole body scanner can provide clinically reliable prediction equation to assess adiposity. 3D whole body scanner provides a fast and precise alternative where the scanner gives upto 140 measurements within a few seconds. Intra-and inter-individual error margins in traditional anthropometric measurements frequently arises for large sample studies, besides, manually taking measurements are time-consuming and challenging to perform within acceptable limits. Six hundred and eight (608) healthy adults were scanned using a 3D whole body scanner and their body composition was measured using the Tanita Bipodal bioelectrical impedance analysis (BIA). 486 formed the development group (for the prediction equation) and 20% of the total (i.e. 122 formed the validation group) based on alphabetical order of participant’s name. Linear regressions were performed to predict an equation wherein the body circumferential measurements like Waist Girth, Hip Girth and Chest Girth were predictors and Fat Mass was the dependent variable. Results: Predictive body composition equation based on volumetric body circumference (girth) proposed for healthy Indian males is FM = 0.420 (Waist Girth) + 0.241 (Chest Girth) + 0.051 (Hip Girth) 51.817. The predicted fat mass value was used for the validated population and we did not see much of a difference between the predicted and measured fat mass. The mean age among the 608 volunteers was 32.54 ± 6.3 years, weight was 71.26 kg ±7.8 kg and BMI was 24.1 ± 2.57 kg/mt. Average difference between body fat measured by BIA predicted body fat mass was 0.13 kg, median 0.50 kg, IQR: 0.80 to 0.20 kg, adjusted R 0.74. Conclusions: 3D whole body scanner technology offer defined and accurate automated anthropometric dimensions and measurements of body shape. Further studies are warranted to reveal important relationships between body shape, body composition and metabolic health across sex, age, BMI and ethnicity groups.