Complete elemental characterization of Molybdenum sulfide, an electro-catalyst for hydrogen evolution reactions, is essential without much compromise on the material integrity. Energy dispersive x-ray fluorescence (EDXRF) spectrometry can non-destructively determine the chemical composition. Mo and S were determined by EDXRF, after addressing the matrix interferences. The interferences due to attenuation of characteristic low energy x-rays of S by the Mo-matrix and overlap of S and Mo characteristic x-rays, lead to rotational and translational matrix effects. These effects on calibration curves were corrected by adopting multiple standard additions, along with matrix correction factors. Herein, the pragmatic inferences, obtained via optimization of experimental variables, were combined with a theoretically calculated correction factor, to solve the extreme spectral overlap problem, during S determinations in the presence of Mo. The results were validated using QC standards and the methodology was applied for real sample analyses. Accuracies better than +/- 5% were achieved.

Sorption of Pd from acidic media was investigated using laboratory synthesized resorcinol–formaldehyde discs, functionalized with thiourea. The discs were characterized via SEM–EDS, FT-IR and EDXRF spectrometry. Pd-sorption efficiencies of the discs, evaluated using both inactive and radiotracer solutions, were compared to those of conventional strong anion exchange membranes. It was established that the disc forms are well-suited for batch separations, wherein very large volume reduction factors are the major goals. Among various de-sorbents studied, 1 M NaOH was found to be the best ( 50

The generation of long-lived 94Nb radioisotope in Zr-2.5Nb pressure tubes has become a major concern. Isolating 94Nb from discharged pressure tubes could potentially reduce the volume of radioactive waste, while the recovered Zr could be reused in fabricating pressure tubes. A robust solvent extraction method was developed for the selective extraction of Nb from a mixture of Zr and Nb. Nb was extracted from an aqueous HCl solution using alpha-benzoin oxime as a ligand dissolved in chloroform. The optimal concentration range of HCl in the aqueous phase for the extraction was found to be 4 to 7 M. About 0.4 % of alpha-benzoin oxime in the organic phase was found to be the optimal ligand concentration to achieve maximum extraction. About 5 min of equilibration time and four separation cycles are adequate for achieving quantitative extraction. The metal concentration in the feed solution exhibits negligible interference with the extraction of Nb into the organic phase. The method effectively separates long-lived 94Nb from discharged pressure tubes, demonstrating its practical applicability.

Resorcinol–formaldehyde polycondensates—the well-established Cs-selective agents, along with their crown ether (18-crown-6) composite discs, were synthesized, characterized (FT-IR, SEM–EDS, surface area, porosity) and applied for strontium uptake from aqueous solutions. Effects of crown ether amounts, Sr in feed, pH, equilibration time, temperature, competing ions, on the sorption, along with re-usability of synthesized sorbents, were evaluated. The fate of Sr was followed by EDXRF spectrometry on both solution and solid phases. Solution pH (3–12) and temperature (upto 100 °C) had negligible impact on the holding capacities. Sorption capacity was enhanced by 33

Four-factor (oxalic acid concentration, contact time, temperature, ultra-sound), two-level experimental design was applied during the recovery of 231Pa from siliceous cake—a solid radioactive-waste, produced in monazite processing. Oxalic acid (0.5 to 1.1 M) had the highest positive (F = 1018.6) and ultrasound had the least (F = 33.0) impact on recovery. All inter-factor interactions were significant, as Fcalculated < Fcritical and P < 0.05. Enthalpy of protactinium-oxalate complexation was found to be − 24.8 kJ mol−1. The regression coefficient (0.9853), randomness and magnitude (< ± 2) of fitted residuals explicated the suitability of present statistical model for predictive analysis.

Goa is a popular destination for migrants from other states. However, according to Census 2011, migration for business comprises only 2.7% of all migration. Using Census data, this study seeks to identify the factors that determine business migration to Goa. It is found that while the size of population of the home state positively influences outmigration, distance has a dampening effect, though its importance as a deterrent is declining over time. The variables of literacy and GSDP do not exert much influence on the volume of migration. A field study conducted to gain insights into the experiences of the business migrant community in Goa shows that most of the respondents have a favourable opinion about Goa, with very few cases of discrimination and abuse.

Indian nuclear energy program adopts the closed fuel cycle, which involves reprocessing of the spent fuel and offers an option for the recovery of valuables from radioactive waste. Some of the useful isotopes present in radioactive wastes, of societal and industrial applications, are Cs-137, Sr-90, Platinum Groups Metals (PGMs: Pd, Rh, and Ru), Pu-238, Am-241, etc. Among PGMs, Ru is used in electrical, electrochemical industries and radioactive isotope of Ru is being applied for the treatment of eye cancer. In the present work, we are focusing on the pre-concentration of Ru from aqueous media by sorption method. Sorption studies were carried out using inactive Ru as well as its radiotracers. EDXRF, & gamma;-ray spectrometry and spectrophotometry were used as the tools for monitoring the sorption processes. For preliminary studies, polyaniline and manganese dioxide were used as sorbents. The sorption was found to be better using polyaniline. For the ease of separation process, composite polymers of aniline with tetraethoxysilane were synthesized and used. The composites were characterized using SEM-EDS, FTIR and elemental analysis techniques. Sorption studies with and without presence of Zr were done with the aim of separation of radioactive Ru from irradiated Zr alloy and recovery of Ru.

Calibration is the primary step in most of the instrumental analytical techniques. Separate calibration standard solutions of Mn, Co were prepared by dissolution of MnSO4·H2O and Co metal in HNO3 media. Neutron activation analysis and energy-dispersive X-ray fluorescence spectrometry were used for assay, homogeneity and stability assessments of these solutions. During the whole preparation, assessment processes, all care was taken to maintain an unbroken chain of comparisons, to establish the traceability of the present solutions to NIST reference standard solutions. The role of appropriate concentration range for multi-point calibration procedures was explicit by closely monitoring the intercept and slope of the least square curve. Accuracies of the measurements for different concentration ranges were compared in terms of the

Abstract Determination of impurities in graphite is very important for its quality control, as their presence even at trace level can affect the performance of graphite in various applications. Graphite with equivalent boron content (EBC) less than 5 mg kg-1 is considered as nuclear grade. Elements with high neutron absorption cross section (boron and rare earths) contribute significantly to EBC. Non-destructive method is preferred as there is no sample processing and probability of loss of volatile elements while digestion. Proton Induced Gamma Ray Emission (PIGE), Instrumental Neutron Activation Analysis (INAA) were utilized for the non-destructive determination of impurities in both nuclear and commercial grade graphite. Low Z elements like Li, B, F, Na, Al and Si were detected in graphite by PIGE whereas Na, K, Sc, Cr, Mn, Fe, Co, Zn, Rb, Zr, Sb, Cs, La, Ce, Nd, Sm, Eu, Tb, Yb, Hf, Ta, Th were determined using INAA. Few elements like Ca, Ti, V, Ni, Sr and Pb remained undetected by both the non-destructive techniques. These elements were determined by Total Reflection X-ray Fluorescence (TXRF) after digestion of the graphite samples by dry ashing. Combinations of these techniques were utilized to get maximum information regarding the impurities present in graphite. GRAPHICAL ABSTRACT

An in-house radiochemical procedure for the separation of Pa-231 from siliceous cake - a waste stream of monazite processing plant, followed by its determination using gamma ray spectrometry, has been developed in our laboratory. Evaluation of reliability of analytical results of the radiochemical procedure is important for validating the fitness of purpose of an analytical method. The present paper describes the statistical evaluation of the analytical results obtained, by estimating the overall uncertainty in the measurement process. The bottom-up approach, also called as ISO approach (ISO/IEC guide 98-3:2008), was adopted to evaluate the overall uncertainty in which the individual sources were identified, evaluated and propagated. The major contribution to the combined uncertainty in measurement of Pa-231 was from efficiency calibration. Besides this, counting statistics in the sample and chemical yield of the process incorporated significant contribution to combined uncertainty. The precision of the results obtained was found to be acceptable, as ascertained by the Horwitz Ratio, for the performance of a single laboratory.

Various aspects of the intensity ratio method of EDXRF, as applied to binary carbonate mixtures of Sr and Ca, are illustrated.

Nitrate (NO3-) is one of the most common contaminants of water bodies with harmful effects to aquatic life and human beings. There is a need for development of sorbents for effective removal of NO(3)(-)form aqueous streams. The aim of present study was to develop a Polyaniline modified halloysite nanoclay (PAni-HC) composite sorbent for the uptake of NO(3)(-)from aqueous medium. Aniline coated on halloysite clay was oxidised in acidic medium at 4oC to synthesise PAni-HC composite in one pot reaction. Successful incorporation of polyaniline (PAni) in the clay matrix was confirmed by different surface characterisation techniques. The as synthesised PAni-HC composite sorbent was tested for NO(3)(-)sorption in a batch mode in the initial concentration range of 5-500 mg L-1. The analysis of NO(3)(-)was performed using ion chromatography in the suppressed conductivity mode. The experimental data were assessed using different kinetic and equilibrium models for understanding the sorption behaviour of the PAni-HC composite. Sorption followed pseudo second order kinetics and intraparticle diffusion model. The maximum Langmuir sorption capacity of PAni-HC composite for NO(3)(-)was found to be 27.9 mg g(-1). The composite sorbent when treated with groundwater samples exhibited quantitative removal (> 90%) of NO(3)(-)thus demonstrating the applicability of the sorbent in real situations.

The results showed that neem leaf powder was the most effective treatment with a record of the highest mean adult mortality of 67.22 per cent and also exhibited the lowest weight loss of 0.67 per cent after 60 days of treatment. It was followed by powders of Eucalyptus (58.89% & 0.87%) and Tulsi (51.11% & 0.80%). The least effectiveness of turmeric rhizome powder against the pest recording minimum adult mortality and maximum weight loss of 30.56% and 1.07% per cent respectively was noticed control against adult mortality (30.56 %), grain weight loss and adult emergence owing to T. castaneum. As a result, 1.5 g/100 g of grains of neem leaf powder can be recommended as a safe control method against T. castaneum in stored wheat. The overall mean adult mortality of T. castaneum in fenvalerate was 72.78 per cent. When it came to treating T. castneum with some inert materials, boric acid treatment was the most effective showed the 100 percent adult mortality, followed by coal ash (71.67 %) and cow dung ash (63.33 %) after 5 days of storage. There was minimum grain weight loss and least adult emergence was recorded in the treatment of coal ash and cow dung ash. Whereas sawdust resulted in the least effective treatment with mean adult mortality of (35.56 %), there was maximum adult emergence seen.

This work focuses on the selective separation of Co from Zr and Nb, for the decontamination of pressure tubes from pressurized heavy water reactor. Initial experiments were carried out using the respective radiotracers. These laboratory scale studies explore the feasibility of using oxalic acid, a benign complexing medium, for the Zr-Nb matrix, with targeted sorption of trace levels of 60Co on cation exchange membranes. Sorption of Co(II) on the membrane followed pseudo second order kinetics and the equilibrium capacity was 1.89 meq g-1. Oxalic acid concentration was a trade-off between the loading of matrix elements and the % sorption of Co(II). Energy dispersive X-ray fluorescence (EDXRF) spectrometry was used for monitoring the sorption of Co on the membrane from inactive sample solutions. Sorption improved the EDXRF detection limits for Co from 50 μg in solution to 1.3 μg on the membrane, where the total concentration of the matrix elements in solution was 50 g L-1. EDXRF method was validated by spike recovery and radiotracer studies.

Calibration of the energy dispersive X-ray fluorescence (EDXRF) spectrometer, using pure elemental standard solutions of Cu, Zr, Nb, Mo, Ta, and U, was carried out and the instrumental sensitivity was derived for each. The effects of the presence of the rest of these elements on the calibration of Zr were evaluated by analyzing the respective binary solutions, separately. All the matrix elements led to a reduction in the Zr- sensitivity of the spectrometer. Intercepts of the calibration curves were found to decrease with Cu, Mo. Nb, Ta, and U led to the elevation of the intercepts. The highest specific changes (per mg of the matrix) in both the slope and intercept were observed upon the addition of Mo. Numerically, these values were -5,917 and -1,187 respectively. Limits of detection for Zr, from the calibration curve, were the best (0.28 & mu;g) in the presence of 7.8 mg Mo and the worst (165.4 & mu;g) in the presence of 53 mg U. The results were validated by multiple standard additions on a sample and analysis of reference standard solution of Zr. Quality control sample analysis re-affirmed the accuracy of the present results. Repeatability was also established for the measurements of solution samples.

The importance of Pomegranate (Punica granatum L.) being economical, medicinal valued fruit and also rich in vitamins. It’s an epitome of health, fertility and eternal life. However, Pomegranate is facing a threat through important diseases like anthracnose, caused by Colletotrichum gloeosporioides Penz. The threat is so severe that it affects the fruit at orchard and post-harvest stages as a result, yield and quality reduction along with marketability loss. The solution to this threat is through biological approach, which means the induction of the seven fungal isolates were evaluated by dual culture technique for their antagonistic activity against Colletotrichum gloeosporioides under invitro conditions is more eco-friendly than chemical approach. Among seven isolates the maximum inhibition of mycelial growth (73.50%) was noticed in Trichoderma harzianum (Madanapalle field isolate) which was followed by Trichoderma viride (Palamaner field isolate) (60.43%). Least inhibition was observed in Trichoderma harzianum (Punganur field isolate) (29.70%). The results indicated that the application of these fungi successfully reduces the anthracnose incidence and also increases the yield of the Pomegranate fruits.

TXRF spectrometry has been utilized for the determination of impurities in copper metal. Multielement standard solution has been used for the calibration of TXRF spectrometer. To avoid the matrix effects, Cu was separated by electrochemical separation method under optimized condition followed by determination of impurities using TXRF. K, Ca, Fe, Ni, and Zn are the impurities found to be present in copper metal. Bottom up approach was employed to get the measure of the combined uncertainty in the results. The uncertainty associated with the recovery of electrochemical separation process is the highest. The TXRF results were validated by analyzing the same sample using ICP‐OES. Student's t‐test was performed to establish the statistical indistinguishability of the results obtained from TXRF and ICP‐OES.

High purity quartz was analyzed using Total Reflection X-Ray Fluorescence (TXRF) spectrometry, during our participation in proficiency testing programme. The sample was digested in HF-HNO3 medium and the silica matrix was removed as silicon tetra fluoride by evaporation and repeated treatments with HNO3. Trace metallic impurities viz. K, Ca, Ti and Fe were quantified via the internal standard (using Ga) method in TXRF spectrometry. The z-score, zeta score and quality control sample analysis revealed the accuracy of the present determinations for all the analytes. Combined uncertainty for the measurement was evaluated through the bottom-up approach. Relative sensitivity of the TXRF spectrometer for the analyte with respect to the internal standard was found to hold the highest share of uncertainty. Detection limits for both the process blank and sample solutions were compared. Detection limits in the sample solutions were 1.86, 0.95, 0.94 and 0.30 mg kg(-1) for K, Ca, Ti and Fe respectively. These studies brought out the importance of appropriate concentration of standard solutions for calibration and sensitivity measurements of the spectrometer, in addition to the quality of reference standard solution, for ensuring accuracy of the results.

A methodology has been developed for the complete compositional characterization of lithium titanate (LTO) using neutron activation, which is quite challenging and no literature report is available so far. The concept of thermal neutron induced in-situ chain reactions 6Li(n,α)3H and 16O(3H,n)18F has been used for the determination of Li and O through the measurement of 18F activity. The method is capable of analyzing Li and O in percentage level as reported in the present analysis of two types of lithium titanate samples. Spectroscopic interference of the elements which can directly or indirectly affect the outcome, were evaluated meticulously. Determination of Ti was carried out using fast neutron activation through the product isotopes like 47Sc, 48Sc, generated via (n,p) nuclear reactions. Fast neutron activation methodology seems to be advantageous for Ti determination over thermal neutron activation, as it offers self validation through different isotopes and multiple gamma lines.

Siliceous cake, a waste from monazite processing plant at Aluva, Kerala, is a rich and natural source of protactinium (231Pa). Protactinium was recovered from this source using oxalic acid as a leaching agent. Field Emission Scanning Electron Microscopy, Energy Dispersive Spectrometry, Energy Dispersive X-ray Fluorescence and gamma spectrometry were utilized for the analysis of streams of the hydrometallurgical process for beneficiation of 231Pa from siliceous cake. Field emission scanning electron microscope equipped with energy dispersive spectrometer was used to assess morphology, particle size, and elemental composition. The results were helpful to understand the effects of these parameters on the leaching of 231Pa. X-ray and gamma ray spectrometric measurements were carried out to determine inactive elements and radionuclides present in the samples, respectively. The data gave an insight into the chemistry of the recovery process for 231Pa and also helped in optimizing the experimental procedure to improve the efficiency of the leaching process. It also gave information about the elements/radionuclides accompanying 231Pa during its recovery from the source material which will help in devising a procedure for its purification.