Kinetic separation of cobalt from zirconium by cation exchange process

Zirconium-tin alloys are used as pressure tubes in Indian pressurized heavy water reactors (PHWRs). Used pressure tubes contain neutron activation products of the constituent elements. ⁶⁰Co is one of the long-lived radioisotopes of concern, for both radioactive waste management and recycling of pressure tubes. This article describes a facile cation exchange separation of Co(II) from Zr(IV) in HCl medium. Co(II) could be preferentially sorbed on the gel resin by utilizing its faster kinetics. Higher flow rates and shallow resin bed were the key steps, which prevented the loading of Zr(IV) on the resin phase.     

Electrochemical lithium insertion behavior of FeNbO4: Structural relations and in situ conversion into FeNb2O6 during carbon coating

Electrochemical properties of FeNbO₄ as a lithium insertion anode material were studied with a view to understand structure–property relationships. Orthorhombic and monoclinic polymorphs of FeNbO₄ were synthesized and characterized by powder X-ray diffraction and laser Raman spectroscopy. Possible redox reactions, as deciphered from cyclic voltammograms, suggest the structural similarity between orthorhombic and monoclinic polymorphs upon lithium insertion. A coating of carbon led to a remarkable improvement in the electrochemical performance of monoclinic FeNbO₄. The coated material exhibited an average reversible capacity of 125.5 mAh g⁻¹. The material also sustained hundreds of charge/discharge cycles and exhibited good rate capability. Upon coating with carbon, the monoclinic FeNbO₄ transformed into FeNb₂O₆. The conversion and stability were confirmed by powder XRD and laser Raman studies of carbon-coated material before and after 450 cycles. The in situ conversion of FeNbO₄ into FeNb₂O₆ during carbon coating was further supported by EPR studies in which the absence of signal for the carbon-coated material indicated conversion of Fe³⁺ to Fe²⁺. Our study reveals the possibility of exploring potential materials in the Fe–Nb–O system and enhancing their performance as anode materials for lithium-ion batteries.     

Bit error rate and reliability analysis of cooperative communication in free-space optical systems

We have investigated the performance and reliability improvement of cooperative free-space optical (FSO) communication over single input single output (SISO) system in this paper. The bit error rate (BER) analysis with quadrature phase shift keying (QPSK), gamma–gamma channel model and pointing error has been demonstrated for SISO and cooperative system. The performance improvement with different combining techniques in cooperative system for different channel environments has been shown in the paper. Markov models for reliability analysis of FSO systems in SISO and cooperative communication have been developed. We have obtained significant increase in availability and mean time between failures with cooperative communication over SISO model.     

Control of ferroelectric phase transition in nano particulate NBT–BT based ceramics

Lead free relaxor NBT–BT based ceramic compositions were prepared using sol–gel method. The samples were sintered around 1140 °C for 3–4 h in the air. The characterization was done using X-ray diffraction (XRD), filed emission scanning electron microscope (FESEM), energy dispersive spectrometry (EDS), Raman, Fourier transform infrared (FTIR), dielectric and P–E loop measurements. The XRD patterns recorded at room temperature confirmed the phase formation of the samples. From FESEM micrographs, the particle sizes were estimated for calcined powders and are found to be in the range of 50–70 nm. The analysis of both Raman and FTIR spectral data of the samples also indicated the distortion of NBT lattice with the addition of Ba²⁺ and Nd³⁺ ions. It was found that the dielectric and piezoelectric properties of NBT–BT compositions beyond the morphotrophic phase boundary (MPB) are rather sensitive to the presence of tetragonal phase in addition to the rhombohedral phase. NBT ceramics exhibit a decrease in diffusive factor with increasing BT content, implying a degradation of relaxor feature leading to the normal ferroelectric nature. The ceramic samples employed in the present study exhibited variation in P–E hysteresis loops.     

Nano‐encapsulated Tinospora cordifolia (Willd.) using poly (D,L‐lactide) nanoparticles educe effective control in streptozotocin‐induced type 2 diabetic rats

The therapeutics for type 2 diabetes mellitus has emerged in the current century towards nanomedicine incorporated with plant active compounds. In this study, Tinospora cordifolia loaded poly (D, L‐lactide) (PLA) nanoparticles (NPs) were evaluated in vivo for their anti‐hyperglycemic potency towards streptozotocin‐induced type 2 diabetic rats. T. cordifolia loaded PLA NPs were synthesised by the double solvent evaporation method using PLA polymer. The NPs were then characterised and administrated orally for 28 successive days to streptozotocin‐induced diabetic rats. The PLA NPs had significant anti‐diabetic effects which were equal to the existing anti‐diabetic drug glibenclamide. The antidiabetic activity is due to the synergism of compounds present in stem extract of the plant which reduced the side effects and anti‐diabetic.Inspec keywords: blood, nanofabrication, drug delivery systems, biochemistry, evaporation, nanoparticles, nanomedicine, drugs, diseases, polymers, biomedical materialsOther keywords: PLA nanoparticles, antidiabetic effects, nanoencapsulated Tinospora cordifolia, streptozotocin‐induced type 2 diabetic rats, type 2 diabetes mellitus, poly(d, l‐lactide) nanoparticles, diabetic drug glibenclamide, nanomedicine, antihyperglycemic potency, double‐solvent evaporation     

Effects of Amelanchier fruit isolates on cyclooxygenase enzymes and lipid peroxidation

Bioassay-directed isolation and purification of the ethyl acetate and methanol extracts of Amelanchier canadensis resulted in 1,3-dilinoleoyl 2-olein (1), 1,3-dioleoyl 2-linolein (2), 5-hydroxymethyl-2-furfural (3), 5-(sorbitoloxymethyl)-furan-2-carboxaldehyde (4), 5-(mannitoloxymethyl)-furan-2-carboxaldehyde (5), and 5-(α-d-glucopyranosyloxymethyl) furan-2-carboxaldehyde (6). Four compounds, oleanolic acid (7), ursolic acid (8), kaempferol-3-O-α-l-rhamnopyranosyl (1 ← 2) rhamnopyranoside (9), and kaempferol-3-O-α-l-rhamnopyranoside (10) were isolated from the ethyl acetate extract of fresh fruits of Amelanchier arborea. The compounds were isolated and purified by various chromatographic techniques and characterized by NMR and GC/MS methods. The isolated compounds inhibited lipid peroxidation (by 85%) at 100 ppm when compared to 89%, 87%, and 98% for the commercial antioxidants butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT), and tert-butylhydroxyquinone (TBHQ) at 1.67, 2.2, and 1.67 ppm, respectively. Although not selective, some of these compounds inhibited cyclooxygenase (COX)-1 and -2 enzymes. Compounds 3–6 were isolated for the first time from A. canadensis and compounds 7–10 were isolated for the first time from A. arborea fruits.     

Intelligent Deep Convolutional Neural Network Based Object Detection Model for Visually Challenged People

Artificial Intelligence (AI) and Computer Vision (CV) advancements have led to many useful methodologies in recent years, particularly to help visually-challenged people. Object detection includes a variety of challenges, for example, handling multiple class images, images that get augmented when captured by a camera and so on. The test images include all these variants as well. These detection models alert them about their surroundings when they want to walk independently. This study compares four CNN-based pre-trained models: Residual Network (ResNet-50), Inception v3, Dense Convolutional Network (DenseNet-121), and SqueezeNet, predominantly used in image recognition applications. Based on the analysis performed on these test images, the study infers that Inception V3 outperformed other pre-trained models in terms of accuracy and speed. To further improve the performance of the Inception v3 model, the thermal exchange optimization (TEO) algorithm is applied to tune the hyperparameters (number of epochs, batch size, and learning rate) showing the novelty of the work. Better accuracy was achieved owing to the inclusion of an auxiliary classifier as a regularizer, hyperparameter optimizer, and factorization approach. Additionally, Inception V3 can handle images of different sizes. This makes Inception V3 the optimum model for assisting visually challenged people in real-world communication when integrated with Internet of Things (IoT)-based devices.