Investigation of Nd3+ incorporation in Ce-rhabdophane: Insight from structural flexibility and occupation mechanism

LnPO₄ · 0.667H₂O rhabdophane has been considered as a potential material for the precipitation of actinides from radioactive waste liquid, owing to its outstanding characteristics of high actinide bearing and easy synthesis in acid solutions. However, a comprehensive understanding of the actinide occupation and the precipitation response of rhabdophane to remove actinides has yet to be established. In this study, the effect of ions concentration and pH values on the detailed precipitation reaction of Ce_xNd_1-xPO₄ · 0.667H₂O rhabdophane in acid solutions are systematically investigated. Some specific issues such as structural distortion and flexibility, and occupation mechanism are discussed by combining with experiments and density functional theory (DFT) calculation. The results reveal that ions concentration and pH values have a significant impact on the crystallization nucleation step before 12 h. The obtained removal rate of Nd³⁺ is more than 99% in pH 1–5 solutions with the ions concentration of 0.05–0.1 mol/L. Moreover, incorporating Nd in CePO₄ · 0.667H₂O rhabdophane will easily result in the lattice distortion in b-axis. DFT calculation and X-ray photoelectron spectroscopy (XPS) results reveal that Nd is preferentially incorporated in nonhydrated site to form a weaker binding energy of NdO₈ polyhedron.     

Differential Physio-Biochemical and Metabolic Responses of Peanut (Arachis hypogaea L.) under Multiple Abiotic Stress Conditions

The frequency and severity of extreme climatic conditions such as drought, salinity, cold, and heat are increasing due to climate change. Moreover, in the field, plants are affected by multiple abiotic stresses simultaneously or sequentially. Thus, it is imperative to compare the effects of stress combinations on crop plants relative to individual stresses. This study investigated the differential regulation of physio-biochemical and metabolomics parameters in peanut (Arachis hypogaea L.) under individual (salt, drought, cold, and heat) and combined stress treatments using multivariate correlation analysis. The results showed that combined heat, salt, and drought stress compounds the stress effect of individual stresses. Combined stresses that included heat had the highest electrolyte leakage and lowest relative water content. Lipid peroxidation and chlorophyll contents did not significantly change under combined stresses. Biochemical parameters, such as free amino acids, polyphenol, starch, and sugars, significantly changed under combined stresses compared to individual stresses. Free amino acids increased under combined stresses that included heat; starch, sugars, and polyphenols increased under combined stresses that included drought; proline concentration increased under combined stresses that included salt. Metabolomics data that were obtained under different individual and combined stresses can be used to identify molecular phenotypes that are involved in the acclimation response of plants under changing abiotic stress conditions. Peanut metabolomics identified 160 metabolites, including amino acids, sugars, sugar alcohols, organic acids, fatty acids, sugar acids, and other organic compounds. Pathway enrichment analysis revealed that abiotic stresses significantly affected amino acid, amino sugar, and sugar metabolism. The stress treatments affected the metabolites that were associated with the tricarboxylic acid (TCA) and urea cycles and associated amino acid biosynthesis pathway intermediates. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and heatmap analysis identified potential marker metabolites (pinitol, malic acid, and xylopyranose) that were associated with abiotic stress combinations, which could be used in breeding efforts to develop peanut cultivars that are resilient to climate change. The study will also facilitate researchers to explore different stress indicators to identify resistant cultivars for future crop improvement programs.     

Synthesis,optimization and characterization of PVA-co-poly(methacrylic acid) green adsorbents and applications in environmental remediation

Polymer Bulletin - The present paper is focused on the synthesis and optimization of a green PVA-co-poly(MAA) adsorbent by free radical polymerization using N,N′-methylene-bis-acrylamide and...     

Fabrication and optimization of polypyrrole/cerium oxide/glassy carbon sensing platform for the electrochemical detection of flupirtine

Journal of Applied Electrochemistry - In spite of single nanomaterials, nanocomposites have come to be the superior modifying materials for electrochemical sensing. Herein, the highly...     

Quantification of carbon nanotube dispersion and its correlation with mechanical and thermal properties of epoxy nanocomposites

An experimental study is carried out to quantitatively assess the dispersion quality of carbon nanotubes (CNTs) in epoxy matrix as a function of CNT variant and weight fraction. To this end, two weight fractions (0.05% and 0.25%) of as-grown, oxidized, and functionalized CNTs are used to process CNT/epoxy nanocomposites. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared analysis of different variants of CNTs are used to establish the efficiency of purification route. While the relative change in mechanical properties is investigated through tensile and micro-hardness testing, thermal conductivity of different nanocomposites is measured to characterize the effect of CNT addition on the average thermal properties of epoxy. Later on, a quantitative analysis is carried out to establish the relationship between the observed improvements in average composite properties with the dispersion quality of CNTs in epoxy. It is shown that carboxylic (-COOH) functionalization reduces the average CNT agglomerate size and thus ensures better dispersion of CNTs in epoxy even at higher CNT weight fraction. The improved dispersion leads to enhanced interfacial interaction at the CNT/epoxy interface and hence provides higher relative improvement in nanocomposite properties compared to the samples prepared using as-grown and oxidized CNTs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48879.     

Sequencing of N‐vinyl‐2‐pyrrolidone/glycidyl methacrylate copolymers by one‐dimensional and two‐dimensional nuclear magnetic resonance spectroscopy

Copolymers of N‐vinyl‐2‐pyrrolidone (V) and glycidyl methacrylate (G) monomers of different compositions were prepared by free‐radical solution polymerization. The copolymer composition of these copolymers was determined with ¹H‐NMR spectra. The reactivity ratios calculated from the Kelen–Tudos and nonlinear least‐square error‐in‐variable methods were r_V = 0.03 ± 0.01 and r_G = 5.05 ± 0.84 and r_V = 0.02 and r_G = 4.72, respectively. The triad sequence distribution in terms of V and G centered triads was determined from ¹³C{¹H}‐NMR spectroscopy. The complete spectral assignment of ¹³C{¹H}‐ and ¹H‐NMR spectra was performed with the help of distortionless enhancement by polarization transfer and two‐dimensional ¹³C–¹H heteronuclear single quantum coherence. The ¹H–¹H couplings were explained with total correlation spectroscopy and nuclear Overhauser enhancement spectroscopy spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 50–60, 2002; DOI 10.1002/app.10186     

Numerical simulation and experimental investigation of gas–powder flow from radially symmetrical nozzles in laser-based direct metal deposition

Laser-based direct metal deposition (DMD) is a solid freeform fabrication process capable of fabricating fully dense and metallurgically sound parts. The process has been greatly enhanced toward multi-directional deposition by the use of discontinuous radially symmetrical powder nozzles to supply the build material. Since many operational parameters depend on the gas–powder stream characteristics between the nozzles and the deposition point, an extensive understanding of the gas–powder flow is necessary. Three-dimensional (3D) multi-phase gas–powder flow structures of radially symmetrical nozzles are modeled using computational fluid dynamics methods. The obtained results are in good agreement with the experimental ones, and they provide a good insight into the process phenomena.     

Chemopreventive Effect of Different Ratios of Fish Oil and Corn Oil in Experimental Colon Carcinogenesis

n-3 Polyunsaturated fatty acids (PUFA) have a chemopreventive effect while n-6 PUFA promote carcinogenesis. The effect of these essential fatty acids may be related to oxidative stress. Therefore, the study was designed to evaluate the effect of different ratios of fish oil (FO) and corn oil (CO) in the prevention of colon cancer. Male Wistar rats were divided into control, dimethylhydrazine dihydrochloride (DMH) treated, FO + CO (1:1) and FO + CO (2.5:1). All the groups, except the control received a weekly injection of DMH for 4 weeks. The animals were sacrificed either 48 h later (initiation phase) or kept for 16 weeks (post initiation phase). DMH treatment in the initiation phase animals showed mild to moderate inflammation, decreased ROS and TrxR activity, increased antioxidants, apoptosis and ACF multiplicity. The post initiation study showed severe inflammation with hyperplasia, increased ACF multiplicity and ROS levels, a decrease in antioxidants and apoptosis. The FO + CO (1:1) treated animals showed severe inflammation, a decrease in ROS, an increase in antioxidants and apoptosis in the initiation phase. FO + CO (1:1) in the post initiation phase and FO + CO (2.5:1) in the initiation showed mild inflammation, increased ROS, apoptosis and decreased antioxidants. There was a decrease in ACF multiplicity and ROS levels, increased antioxidants and apoptosis in the post initiation phase study. The present study suggests that FO has a dose- and time-dependent chemopreventive effect in colon cancer mediated through oxidative stress and apoptosis.     

A Discrete Water Cycle Algorithm for Cellular Network Cost Management

Wireless Personal Communications - Water Cycle Algorithm (WCA) is a nature-inspired metaheuristic algorithm. There is a lack of literature surrounding the use of WCA in modern cellular mobile...     

Aesthetical design of a car profile: a Kano model-based hybrid approach

An amicable aesthetical design of a product is prudent for its wide acceptability and viability. Selection of shape parameters with customer satisfaction is critical in aesthetical design and a challenging task for designers. In the present work, the authors proposed a sequential approach to design a car profile with aesthetical aspects. The methodology is based on Kano model that provides a framework for incorporation of customer satisfaction with the design requirements. Further, Taguchi's robust design approach has been used to find the optimum level of the parameter to achieve initial design estimates and thereafter, response surface method (RSM) is applied to refine the optimum values, precisely. The methodology has been illustrated with a case study.