Structural Stability and Phase Transitions in Zeolite A: An In Situ High Pressure-High Temperature Investigation.

The high pressure-high temperature structural stability of Zeolite A (ZA) has been studied using the X-ray diffraction (XRD) method. Structural studies at high temperatures show a reduction in the oxygen occupancy, belonging to the water molecule, indicating thermal dehydration and subsequent expulsion of water molecules from the pores of the structure. ZA does not undergo structural phase transition with temperature.

Insights into the Coordination Behavior of Methyl-Substituted Phosphinic Acids with Actinides.

The electronic structure and complexation behavior of methyl-substituted phosphinic acids with U(VI) and Pu(IV) were explored by applying quantum chemical methods. In contrast to Ingold's classification, our results indicate that the methyl group is electron-withdrawing, reducing the phosphoryl group electron density in substituted phosphinic acids. The magnitude of the computed complexation energy values increases along with the series, PA → MPA → DMPA, and MP → MMP → MDMP, implying an increasing complexation tendency upon methyl group substitution for both U(VI) and Pu(IV) complexes.

Chromosome length ratio as a biomarker of DNA damage in cells exposed to high dose ionizing radiation.

The premature chromosome condensation (PCC) assay is considered as complementary bio-dosimetry tool for chromosome aberration assay and the PCC assay can be used to estimate high dose exposure. Though the PCC ring is considered as prospective biomarker, chromosome length ratio (ratio of longest and shortest chromosome length in PCC spreads) of chemically induced PCC is shown to be very good indicator of ionizing radiation. In view of this, an in-vitro study has been performed using PCC assay to suggest chromosome length ratio (LR) as potential bio-dosimeter induced by high dose ionizing radiation.

Modulation of intrinsic defects in vertically grown ZnO nanorods by ion implantation.

Intrinsic defects created by chemically inert gas (Xe) ion implantation in vertically grown ZnO nanorods are studied by optical and X-ray absorption spectroscopy (XAS). The surface defects produced due to dynamic sputtering by ion beams control the fraction of O and Zn with ion fluence, which helps in tuning the optoelectronic properties. The forbidden Raman modes related to Zn interstitials and oxygen vacancies are observed because of the weak Fröhlich interaction, which arises due to disruption of the long-range lattice order.

Thermal and rheological properties of magnetic nanofluids: Recent advances and future directions.

Technological advancement and miniaturization of electronic gadgets fueled intense research on nanofluids as potential candidates for cooling applications as a substitute to conventional heat transfer fluids. Among nanofluids, magnetic nanofluids, traditionally known as ferrofluids have attracted a lot of attention owing to their magnetic field tunable thermal conductivity and rheological properties due to the aggregation of the magnetic nanoparticles into chains or columns in the presence of the magnetic field. The field-induced aggregates act as low resistance pathways thereby improving thermal transport substantially.

Analysis of coal ash samples from thermal power plants of India for their gallium content using NAA and EDXRF techniques.

Coal fly ash (CFA) is an important secondary source for the recovery of gallium (Ga) which has a high potential for its wide applications in many strategic fields such as cellular communications and direct broadcast satellite. Various coal fly and bottom ash samples obtained from thermal power plants located in different parts of India were investigated for their gallium content using NAA and EDXRF techniques. The concentration of gallium in NIST SRM 1633b CFA is not available in NIST certificate and hence was established using k based IM-NAA method along with the other certified elements like As, Ce, Co, Eu, Fe, K etc.

Enhanced luminescence of tris(carboxylato)uranyl(VI) complexes and energy transfer to Eu(III): a combined spectroscopic and theoretical investigation.

Complex formation between uranyl and carboxylate ligands (benzoate, nicotinate and isonicotinate) has been studied extensively by absorption and luminescence spectroscopy in acetonitrile medium. Experimental data had indicated the existence of stable and enhanced luminescent tris(carboxylato) uranyl(VI) complexes [UO(L)] with symmetry. The high luminescence of these complexes was due to the sensitization of the O → U ligand to metal charge transfer (LMCT) emission by extremely intense equatorial (carboxylate ligands) LMCT bands.

Unraveling the Complexity of Nano-Dispersoids in the Oxide Dispersion Strengthened Alloy 617.

Nanocrystalline oxides are mainly responsible for Ni-base oxide dispersion strengthened (ODS) superalloys excellent thermo-mechanical properties. To establish the microstructural correlations between the metallic matrix and various oxide dispersoids, we report here the atomic-scale structure and chemistry of the complex nano-oxide dispersoids. Ultrahigh-resolution Cs-aberration-corrected scanning transmission electron microscopy (STEM) based techniques have been used to resolve nano-dispersoids in the Alloy 617 ODS.

Unique O═N...O Pnicogen Interactions in Nitromethane Dimers: Evidence Using Matrix Isolation Infrared Spectroscopy and Computational Methodology.

Geometries of nitromethane homodimers have been revisited using and density functional methodologies, following their formation within cryogenic matrices, confirmed using infrared spectroscopy. In contrast to the claim that the intermolecular interactions are due to dispersion forces or very weak hydrogen bonds, in the present work, concrete evidence for the prevalence of O═N..

Novel Study of Strain-Induced Piezoelectricity in VO.

VO is well known for its dual-phase transitions, electrical and structural, at a single temperature of 340 K. The low-temperature structural phases of VO are different from their high-temperature counterpart in terms of structural symmetry. The strain-induced modification of the structural distortion in VO is studied in detail.

Design, development, and instrumentation of isopiestic experimental setup.

An isopiestic experimental facility for the measurement of vapor pressures has been designed, fabricated, and commissioned. Using the vapor pressure data as a function of temperature, useful thermodynamic properties of alloys and compounds of interest can be derived. The isopiestic facility comprises a pair of furnaces, temperature controllers, thermocouple movement mechanism, user interface, and data collection.

Post synthetically modified IRMOF-3 for efficient recovery and selective sensing of U(vi) from aqueous medium.

A simple and efficient route to develop various novel functionalized MOF materials for rapid and excellent recovery of U(vi) from aqueous medium, along with selective sensing has been demonstrated in the present study. In this connection, a set of four distinct post synthetically modified (PSM) iso-reticular metal organic frameworks were synthesized from IRMOF-3 namely, IRMOF-PC (2-pyridine carboxaldehyde), IRMOF-GA (glutaric anhydride), IRMOF-SMA (sulfamic acid), and IRMOF-DPC (diphenylphosphonic chloride) for the recovery and sensing of U(vi) from aqueous medium. The MOFs were characterized by Fourier transform infrared spectroscopy (FTIR), powder XRD, BET surface area analysis, thermogravimetric analysis (TGA), NMR (C, H and P), Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX).

Interplay of piezoresponse and magnetic behavior in BiAFeO (A = Ba, Ca) and BiBaCaFeO co-doped ceramics.

Extensive piezoresponse force microscopy (PFM) and magnetic force microscopy (MFM) measurements in conjunction with piezoresponse spectroscopy have been carried out on pellets of BiAFeO (A = Ba, Ca) and Bi.Ba.Ca.

High performance asymmetric supercapacitors based on TiCT MXene and electrodeposited spinel NiCoS nanostructures.

Spinel metal sulfides have been investigated for a wide range of applications mostly in electrochemical energy storage owing to their better electronic conductivity and high reversible redox activity. Herein, we report a facile fabrication approach for the binder-free supercapacitor electrodes based on spinel NiCoS (NCS) on various substrates such as Cu-foil (CF), Ni-foam (NF), and vertical graphene nanosheets grown on carbon tape (VG) a single step-controlled electrodeposition technique. The obtained electrodeposited NiCoS grown on Cu-foil (denoted as CF-NCS) in symmetric assembly shows a high specific capacitance of 167.

In vivo appraisal of oxidative stress response, cell ultrastructural aberration and accumulation in Juvenile Scylla serrata exposed to uranium.

In vivo studies were performed to evaluate the organ specific tissue accumulation and cellular toxicity of uranium to mud crab Scylla serrata. The specimens were acclimated in natural seawater and the exposure to 50-250 μg/L uranium was investigated up to 60 days. The present study examined the effects of concentration and duration of uranium exposure in the tissue of S.

ZrO-AgO nanocomposites encrusted porous polymer monoliths as high-performance visible light photocatalysts for the fast degradation of pharmaceutical pollutants.

This work reports a unique ZrO-AgO heterojunction nanocomposite uniformly dispersed on a macro-/meso-porous polymer monolithic template to serve as simple and effective visible light-driven heterogeneous plasmonic photocatalysts for water decontamination. The monolithic photocatalysts' structural properties and surface morphology are characterized using various surface and structural characterization techniques. The photocatalytic performance of the proposed photocatalysts is evaluated by optimizing multiple operational parameters.

Performance of various mathematical functions for the in-situ relative detector efficiency towards its applicability for k IM-NAA.

The in-situ relative detection efficiency strongly influences the characteristics of the k-based internal monostandard neutron activation analysis (IM-NAA). In the present work, various mathematical functions were explored for the establishment of in-situ relative detector efficiency calibration and compared their performance based on the reduced chi-square (χ) values. Among the various mathematical functions, the polynomial logarithm with 6th order was found to be associated with the minimum mean standard deviation for the experimental data and the lowest value of reduced χ after carrying out multiple iterations using Nelder-Mead algorithm.

Precise determination of plutonium in nuclear fuel process samples.

A REDOX-based analytical method was developed for determining the plutonium concentration. In this method, plutonium was oxidized to the +6-oxidation state using of ceric ammonium nitrate solution. The interference from ceric(IV) nitrate was suppressed by reducing its oxidation state from +4 to +3 with sodium nitrite.

Atomic scale insights on the growth of BiFeO nanoparticles.

This study provides new insights on the formation of the nanocrystallites of phase pure BiFeO prepared using sol-gel method with tartaric acid as the fuel as comprehended based on the local structure and magnetic hyperfine fields at Fe sites using Mossbauer spectroscopy. Important steps involved in the growth of the nanocrystallites of BiFeO in the sol-gel reaction are elucidated in a detailed manner in this study for the first time. Three important stages with the second stage marked by the formation of as high as 75% of nanocrystallites of BiFeO occurring over a narrow calcination temperature interval 700-723 K have been deduced in this study.

Unraveling the coordination approach of Eu(III) in cyphos nitrate ionic liquid - a comprehensive luminescence spectroscopy study.

In consideration of the mounting attention drawn by the ionic liquid cyphos 101 (trihexyl(tetradecyl)phosphonium chloride: [P][Cl]) in the recovery of rare earth metals and other valuable species from their waste matrices, an effort was made using luminescence spectroscopy to study the detailed liquid-liquid extraction and coordination behavior of Eu(III) using the nitrate form of cyphos 101 (cyphos nitrate: [P][NO]) in its undiluted form. Eu(III) complexation with [P][NO] at each stage of the extraction process was investigated using the luminescence spectroscopy technique. Various extraction parameters such as aqueous phase acidity, concentrations of ionic liquid extractant and initial Eu(III) ion, extraction time, experimental temperature, were tuned to discover their impact on the complexation process.

Valorisation of algal biomass to value-added metabolites: emerging trends and opportunities.

Algal biomass is a promising feedstock for sustainable production of a range of value-added compounds and products including food, feed, fuel. To further augment the commercial value of algal metabolites, efficient valorization methods and biorefining channels are essential. Algal extracts are ideal sources of biotechnologically viable compounds loaded with anti-microbial, anti-oxidative, anti-inflammatory, anti-cancerous and several therapeutic and restorative properties.

Fiber-A Biogenic Reinforcement Material for Europium Substituted Hydroxyapatite/Poly(3,4-propylenedioxythiophene) Matrix: A Novel Ternary Composite for Biomedical Applications.

Novel multifunctional biocomposite materials that mimic the properties of bone are the need of the hour. In view of this, the current work is focused on the fabrication of a snail shells derived europium-substituted hydroxyapatite (Eu-HAP)/poly(3,4-propylenedioxythiophene) (PProDOT)/ fiber (CGF) ternary composite on titanium (Ti) for biomedical applications. The structural, morphological, mechanical, electrochemical, and biological properties of the as-developed coatings on Ti were characterized.

Highly efficient functionalized MOF-LIC-1 for extraction of U(VI) and Th(IV) from aqueous solution: experimental and theoretical studies.

A set of four new functionalized MOFs, namely MOF-LIC-DPPC, MOF-LIC-GA, MOF-LIC-PCA and MOF-LIC-SA, were synthesized the post-synthetic modification (PSM) strategy using MOF-LIC-1 for efficient extraction of U(VI) and Th(IV) from an aqueous medium. FTIR, powder XRD, TGA and SEM-EDX were employed for characterization of the functionalized MOFs. Sorption studies for U(VI) and Th(IV) were performed by monitoring the pH and contact time.

Phase evolution in thermally annealed Ni/Bi multilayers studied by X-ray absorption spectroscopy.

The thin films of Ni and Bi are known to form NiBi and NiBi compounds spontaneously at the interface, which become superconducting below 4.2 K and show ferromagnetism either intrinsically or due to Ni impurities. Formation of NiBi and NiBi is a slow diffusion reaction, which means the local environment around Ni and Bi atoms may vary with time and temperature.

Design and development of heater control circuit without temperature sensor for monitoring hydrogen in argon.

A thin film based tin oxide sensor is developed to monitor low levels of hydrogen (concentration ranging from 5 to 75 ppm) in the cover gas plenum of the fast breeder test reactor. The heater and the sensor patterns are integrated on a miniature alumina substrate, and necessary electrical leads are incorporated into it. For proper functioning of the sensor, the heater has to be maintained at a constant temperature of 350 °C.