Coal based thermal power plants contribute about similar to 72% of the power generation in India. Indian coal is of bituminous type, having a high ash content with 55-60% ash. Due to considerable environmental importance the collected fly ash has become a subject of worldwide interest in recent years. In the present study radon exhalation rate and the activity concentration of Ra-226, Th-232 and K-40 radionuclides in fly ash samples from Kasimpur Thermal Power Plant, Aligarh, Uttar Pradesh, India have been measured by 'Sealed Can technique' using LR-115 type II detectors and a low-level NaI (Tl)- based gamma-ray spectrometer, respectively. Radon exhalation rate has been found to vary from 57.1 +/- 5.3 to 119.4 +/- 7.7 mBq m(-2) h(-1) with an average value of 87.3 +/- 5.8 mBq m(-2) h(-1). Activity concentration of Ra-226 ranged from 20.0 +/- 8.5 to 30.0 +/- 9.7 Bq kg(-1) with an average value 23.4 +/- 9.0 Bq kg(-1), Th-232 ranged from 17.0 +/- 9.9 to 69.0 +/- 13.8 Bq kg(-1) with an average value of 46.5 +/- 12.1 Bq kg(-1) and K-40 ranged from 130.0 +/- 7.2 to 332.0 +/- 11.1 Bq kg(-1) with an average value of 177.0 +/- 8.1 Bq kg(-1).

A comprehensive assessment of the distribution, spatial mapping and ecological risk of heavy metals in stream sediments of 17 counties of Ireland based on the Tellus geochemical survey programme in Ireland was carried out. Average trace metal concentrations of chromium (Cr), nickel (Ni), copper (Cu), lead (Pb), zinc (Zn), vanadium (V), cobalt (Co), arsenic (As), and major and minor oxides iron oxide (Fe2O3), manganese oxide (MnO) in the stream sediments were above the background values, but lower than Irish sediment quality guidelines for livestock and Canadian sediment quality guidelines (ISQG); threshold effect level (TEL) and probable effect level (PEL). 69.65% of Ni, 22.13% of Zn, and 96.7% of Pb samples exceeded the low-effect-range (ERL) values, whereas only 21%, 1.80% and 0.69% of the same elements exceeded the median effect range (ERM) values. Hotspots of Zn (>12000 mg kg−1), Pb (>10,000 mg kg−1), Fe2O3 (61.38%), MnO (26%), Cr (>2300 mg kg−1) and Ni (874.2 mg kg−1) were observed at Wicklow, Dublin, Mayo, Galway and Cavan counties. Catchment geochemistry was identified for the presence of heavy metals in the stream sediments. The geo-accumulation index (Igeo) indicated Kildare to be the least contaminated county with Igeo < 0 for Cr, Ni, Cu, Zn, Pb and As for 50% of the samples. The enrichment factor (EF) indicated that some sites located in Mayo and Donegal were highly contaminated. P Inemerow followed the trend, Tipperary > Dublin > Waterford > Monaghan > Donegal > Wexford > Galway > Wicklow > Cavan > Meath > Kilkenny > Leitrim > Mayo > Louth > Sligo > Kildare > Carlow. Based on potential ecological risk index (PERI), 83.1% of the sites posed low ecological risk (PERI <150), 11.9% sites posed moderate risk (150 < RI < 300) and high ecological risk was posed by 0.3% (PERI >1200) of the sites. Lithology, topography and anthropogenic factors influenced the distribution and ecological risks of heavy metals. Non-carcinogenic and carcinogenic risk for adults and children were above the recommended value.

Water quality degradation and metal contamination in groundwater are serious concerns in an arid region with scanty water resources. This study aimed at evaluating the source of uranium (U) and potential health risk assessment in groundwater of the arid region of western Rajasthan and northern Gujarat. The probable source of vanadium (V) and fluorine (F) was also identified. U and trace metal concentration, along with physicochemical characteristics were determined for 265 groundwater samples collected from groundwater of duricrusts and palaeochannels of western Rajasthan and northern Gujarat. The U concentration ranged between 0.6 and 260 μg L −1 with a mean value of 24 μg L −1 , and 30% of samples surpassed the World Health Organization’s limit for U (30 μg L −1 ). Speciation results suggested that dissolution of primary U mineral, carnotite [K 2 (UO 2 ) 2 (VO 4 ) 2 ·3H 2 O] governs the enrichment. Water–rock interaction and evaporation are found the major hydrogeochemical processes controlling U mineralization. Groundwater zones having high U concentrations are characterized by Na–Cl hydrogeochemical facies and high total dissolved solids. It is inferred from geochemical modelling and principal component analysis that silicate weathering, bicarbonate complexation, carnotite dissolution, and ion exchange are principal factors controlling major solute ion chemistry. The annual ingestion doses of U for all the age groups are found to be safe and below the permissible limit in all samples. The health risk assessment with trace elements manifested high carcinogenic risks for children.

In this paper we investigate the effect of lanthanum doping on structural, dielectric and electrical properties of lead magnesium niobate - lead titanate, 0.65Pb(Mg1/3Nb2/3O3)- 0.35PbTiO3 (x=0, 0.02, 0.05) ferroelectric ceramics. Dielectric and AC impedance spectroscopic measurements were carried out on pure and lanthanum doped PMN/PT ceramics over a wide temperature (30o- 450o C) and frequency interval (10 Hz-1 MHz). Pure and lanthanum doped Pb1-xLax[(Mg1+x/3Nb2-x/3)0.65Ti0.35(1-x/4)]O3, (x=0, 0.02, 0.05) ceramics were prepared by solid state reaction route using columbite precursor method. X-ray diffraction revealed tetragonal (P4mm) phase for pure PMN/PT ceramics and transition to pseudo cubic phase (Pm3m) was observed with increased lanthanum doping. The dielectric response of the lanthanum modified PMN/PT ceramics was interpreted in terms of modified curie weiss law. Modulus spectroscopy revealed the deviation of dielectric behavior from ideal Debye behaviour. Activation energies calculated from dielectric relaxation and modulus spectroscopy suggested that charge transport processes are due to oxygen ion hopping.The AC conductivity of the PMN/PT ceramics initially increased for 2 mol% of lanthanum doping followed by a subsequent decrease with further 5 mol% of lanthanum doping. The value of the activation energies calculated from the temperature dependance of ac conductivity was in the range from 1.20-1.48 ev which is due to doubly ionized oxygen vacancies. The overall structural, electrical and dielectric behaviour of Pb1-xLax[(Mg1+x/3Nb2-x/3)0.65Ti0.35(1-x/4)]O3, (x=0, 0.02, 0.05) ceramics is correlated to the relaxor nature induced by lanthanum doping.

The present study reveals the distribution of terrestrial radionuclides (Ra-226, Th-232 K-40) and heavy metals (Cr, Ni, Cu, Zn, Pb, Co) from soil samples of Una, Hamirpur and Kangra districts of Himachal Pradesh (India). The Ra-226, Th-232, K-40 activity concentration in the studied region has been varied from 8 to 3593 Bq kg(-1); 21-370 Bq kg(-1)16; 62-7130 Bq kg(-1) respectively. High disequilibrium factor (U-238/Ra-226) depicts that uranium constantly migrates from clay oxidizing zone and getting precipitated with enrichment towards south. An attempt has been made to correlate the distribution of these radionuclides and heavy metals with geology and rock type formation of Siwalik region. The concentration of Pb, Zn and Co was found higher than Indian average background value. Multiple radiological and pollution indices have been estimated for proper risk analysis in the studied region. The annual effective dose in studied region is lower than the recommended limit of 1.0 mSv a(-1). The obtained geoaccumulation index and enrichment factor indicated that the sites located in the Hamirpur and Kangra regions were moderately contaminated with Pb and Co. The Nemerow pollution index and contamination security index suggested that almost 45% sites were slightly to moderately polluted. The non-carcinogenic and carcinogenic risks for both children and adults were within acceptable limits. (C) 2020 Elsevier Ltd. All rights reserved.

The following work is a part of wider uranium prospecting programme of the Atomic Mineral Directorate for Exploration and Research (AMD) for mapping radioactive anomalies in mineralized regions of Siwalik, Himachal Pradesh. This study reports the analysis of average activity concentration, potential radiological hazards; radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin) and excess cancer life time risk (ECLR) calculated due to naturally occurring radioactive materials (NORM); Radium (226Ra), Thorium (232Th) and Potassium (40K) in uranium mineralized zone of Siwaliks for health risk assessment. The geometric mean value of calculated indoor and outdoor annual effective dose in the Una, Hamirpur and Kangra region are 0.88 and 0.22; 1.77 and 0.44; 1.86 and 0.46 mSvy-1 respectively. The average air absorbed dose rate were measured to be 118 nGyh-1 in Una, 163 nGyh-1 in Hamirpur and 135 nGyh-1 in Kangra district respectively. Correlation study indicated good correlation of the measured gamma dose rate and the estimated gamma dose rate with a correlation coefficient of (R2 =0.62). This data provides important information on the radiation risk and spatial variability of the natural terrestrial gamma radiation in the Siwalik region.

This study summarizes the seasonal experimental data on the activity concentrations of indoor 222 Rn (Radon), 220 Rn (Thoron) and their progeny in Mansa and Muktsar districts of Punjab (India) using LR-115 solid state nuclear track detector based time integrated pin-hole cup dosimeters and deposition based progeny sensors for the assessment of radiological dose. The indoor 222 Rn concentration was observed higher in the rainy and winter seasons while 220 Rn concentration was observed higher in the winter season. However, Equilibrium Equivalent Concentrations (EECs) of 222 Rn and 220 Rn exhibited distinct seasonal behaviour unlike their parent nuclides. The average equilibrium factors for 222 Rn (F Rn ) and 220 Rn (F Tn ) were found 0.47 ± 0.1 and 0.05 ± 0.01, respectively. The annual arithmetic means of unattached fractions of 222 Rn ( f_p^Rn ) and 220 Rn ( f_p^Tn ) were found to be 0.09 ± 0.02 and 0.10 ± 0.02, respectively. The attachment rate ( X Rn ) and attachment rate coefficients ( β ) of 222 Rn progeny were also calculated to understand the proper behaviour of progeny species in the region. A new alpha flux based technique has been proposed and used for the assessment of absorbed dose rate and annual effective dose rate for radiation protection purpose.

In the current study, the structural and spectroscopic properties of phosphatic shale samples obtained from the Atomic Minerals Directorate for Exploration and Research were probed for potential use as a phosphor material. X-ray diffraction and Raman and Fourier transform infrared spectroscopy revealed that the beneficiated phosphatic shale samples were primarily monophasic consisting of fluorapatite [Ca5 (PO4 )3 F, (FAP)] with minor traces of haematite (α-Fe2 O3 ) and calcite (CaCO3 ). Energy dispersive X-ray fluorescence revealed the presence of U, Eu, Dy and Tb in the FAP matrix substituted at Ca(I) and Ca(II) sites of FAP. A reduced optical direct band gap of 4.46 eV was calculated from the Tauc plot. Photoluminescence spectral studies revealed multicolour emissions (red, yellow, green and blue) on ultraviolet light excitation that were attributed to luminescence spectra from rare earth ions Eu3+ , Tb3+ , U4+ and U6+ in the FAP matrix. The overall emissions for the rare earth and actinide-doped FAP were obtained in the cool white region and the corresponding Commission Internationale de l'Eclairage chromaticity coordinates were calculated to be (0.274, 0.317). The corresponding colour correlated temperature obtained was 9342 K. Furthermore, phosphatic shale had a high room temperature dielectric constant of 11 at a frequency of 1 kHz that demonstrated its suitability for use in biological sensors. The study showed that natural phosphatic shale could be a potential material for optical, biological and dielectric applications.

The structural and spectroscopic characteristics of phosphatic ferruginous shale samples from the Bijawar Group rocks from Sagar District of Madhya Pradesh (India) have been probed for identification of uranium species. Fluorapatite (\(\hbox {Ca}_{5}\hbox {(PO}_{4})_{3}\hbox {F}\), FAP) and haematite (\(\upalpha \)-\(\hbox {Fe}_{2}\hbox {O}_{3}\)) were identified as the main phases in the separated mineral concentrates. The photoluminescence (PL) and X-ray absorption near edge spectroscopy (XANES) studies pointed to a strong experimental evidence of both U(IV) and U(VI) oxidation states in the mineral concentrate portion obtained from the same parent host rock. The PL spectrum has confirmed the charge transfer (f–d) transition bands in UV and near-UV regions with emission peaks at ca. 290, 313, 336, 399 and 416 nm, which has been attributed to the substitution of \(\hbox {Ca}^{2+}\) ions by U(IV) in FAP and broad structureless emission due to stabilisation of U(VI) as \(\hbox {UO}_{6}^{6-}\) in haematite. Time-resolved spectroscopy studies have revealed biexponential decay components lasting 2–5 ns for U(IV) species and \(10\,\upmu \hbox {s}\) for U(VI) species. These characterisations revealed the fundamental information about the oxidation state and form of uranium in this region. Remediation measures for the Bijawar region are also suggested.

Ultra-small clusters containing few atoms are of high interest in both fundamental research and applications due to their specific functional, magnetic or chemical properties which depend on size and composition. The experimental results of the morphology of the size-selected clusters, consisting of few atoms can be an ideal benchmark for sophisticated theoretical models. With this motivation we have investigated the geometrical structure of mass-selected Au-9 clusters deposited on a silicon substrate prepared by soft-landing conditions. We present results obtained experimentally by Grazing-Incidence Small-Angle X-ray Scattering (GISAXS). Considering the ultra-small size of the clusters and small quantities of material on the surface, we combined advanced techniques which allowed us to investigate the surface structure of the sample. The resulting structural sizes are in concordance with cluster theory. Using a model-based approach, the advanced X-ray techniques allow for understanding how to resolve the possible cluster structure, identify optimal experimental conditions and obtain the probable morphological information which is challenging to be obtained otherwise.

The uranium containing phosphatic shale sub surface samples collected from Bijawar region Madhya Pradesh (M.P.), India as a part of the uranium exploration programme of the Atomic Minerals Directorate for Exploration and Research (AMD), Department of Atomic Energy (DAE) were characterized by a variety of molecular spectroscopic techniques such as photoluminiscence (PL), time resolved photoluminiscence spectroscopy (TRPL), X-ray absorption near edge spectroscopy (XANES), Raman spectroscopy and structural techniques such as X-ray diffraction (XRD) to identify the oxidation state, physical and chemical form of uranium in this region. Oxidation state analysis by fluorescence spectroscopy revealed majority of the samples in U(VI) oxidation state. The most abundant form of uranium was identified as uranate (UO66-) ion, as a substituent of Ca++ in Ca5(PO4)3F, Flourapatite (FAP). Two uranium species in U(VI) and U(IV) state; (UO2)2+ adsorbed on silica and uranium oxide species (UO2) were also identified. The study provided baseline information on the speciation of uranium in Bijawar region.

Non-fermentative Gram negative bacteria (NFGNB) can cause serious infections in hospitalised patients. There has been an increase in resistance to carbapenems which is worrying as they are considered as antibiotics of last resort. Carbapenemases are responsible for carbapenem resistance. Study was undertaken to evaluate antibiotic profile, to ascertain risk factors associated and to detect genes responsible for carbapenem resistance in NFGNB isolates from acute wards of a tertiary care centre. The study was carried out in an urban tertiary care centre. Samples were collected from patients of acute wards and relevant clinical history was collected. Imipenem resistance detection and antibiotic susceptibility was done. A multiplex PCR was done on imipenem resistant isolates for detection of resistant genes. A total of 296 isolates were collected. Acinetobacter baumannii (132) followed by Pseudomonas aeruginosa (121) were the predominant isolates. OXA-51(72) and NDM were the predominant genes detected in Imipenem resistant A. baumannii and Pseudomonas aeruginosa (39). The carbapenem resistance in NFGNB in our hospital setting is mostly because of VIM, NDM, OXA-23, OXA-51. Constant monitoring of the incidence of such organisms in critical areas of the hospital, prompt recognition and getting rid of them is the only important preventive strategy.

Pure yttrium oxide (Y2O3) and Yb doped Y2O3 (Yb: Y2O3) nanocrystalline powders were synthesized by the carbonate solution route which can be used in fabrication of transparent ceramics required for laser host application. Calcination time, temperature and pH were optimized to obtain well separated phase pure nanoparticles. The effect of Yb doping on structure of Y2O3 were studied by X-ray diffraction, transmission electron microscopy (TEM) and Raman spectroscopy. The phase structure was identified to be BCC for Y2O3 and distorted BCC for Yb: Y2O3 samples for 8 mole% doping of Yb. A decrease in lattice volume and homogeneous strain due to decrease in particle size was found to appear with Yb doping. Selected area electron diffraction (SAED) and High Resolution TEM (HRTEM) measurements investigations confirmed the BCC structure and found the nanoparticles to be in the range of 65-80 nm which decreased on Yb substitution. The Raman spectra explain the structural changes due to doping of Yb in Y2O3.

The activity concentration of natural radionuclides and 222Rn (Radon) exhalation rate in soil samples were determined using NaI gamma detector and Scintillation based Smart Radon Monitor (SRM). Soil samples were collected from different geological formations of the same area. The concentration of three radionuclides (226Ra, 232Th and 40K) in the studied area has been varied from 25Bqkg−1 to 48Bqkg−1, 28Bqkg−1 to 47Bqkg−1 and 356Bqkg−1 to 598Bqkg−1 respectively. The average value of 226Ra (Radium) equivalent activity in soil samples of the studied area was 125Bqkg−1. The 226Ra equivalent activities of soil samples have been calculated to assess the radiation hazards arising due to the use of these soils in the construction of dwellings. The exhalation of 222Rn from the earth's crust and building material are the main source of 222Rn in indoor environment. The 222Rn exhalation rate in the studied area was varied from 16.9±0.5mBqKg−1h−1 to 38.2±0.9mBqKg−1h−1. A weak correlation was obtained between the 226Ra and 222Rn exhalation rate. The annual effective doses for different organs and radiation hazards have been also calculated in the studied area. The overall average annual effective dose in the studied is lower than the world recommended value of 1.0mSva−1.

Geometrically frustrated hexagonal BaMnO3 (2H) is an interesting material due to the presence of more than one ferroic order parameters. Although the material is well known, still there exists confusion on the crystal structure of this material at room temperature and its ferroelectric properties have not been explored. Here, we report noncentrosymmetric crystal structure and ferroelectric properties of BaMnO3 (2H) at room temperature. The dielectric diffusivity calculated from modified Curie-Weiss laws and non linear Vogel-Fulcher fittings implies weak relaxor characteristic of BaMnO3 (2H). The ferroelectric properties arise due to off centering of Mn4+ ion in unit cell and weak relaxor properties are attributed to the presence of a smaller amount of Mn3+ cations which creates disorder in 2H-BaMnO3.

Erbium (Er) and lanthanum (La) substituted BiFeO 3 (BFO) ceramics have been prepared through conventional solid solution route. X-ray diffraction data indicated a gradual phase transition from rhombohedral to monoclinic structure in Bi 0·9− x La 0·1 Er x FeO 3 ( x = 0·05, 0·07 and 0·1) (BLEFO x = 0·05, 0·07, 0·1 ) ceramics. Differential thermal analysis (DTA) measurements of BFO samples showed a ferroelectric transition at 835°C, whereas it is shifted to 792°C for BLEFO x = 0·1 . The Raman spectra of BLEFO x = 0·05, 0·07, 0·1 samples showed the shift of Raman modes to higher wavenumbers and suppression of A 1 modes indicating decrease in ferroelectricity. The Raman spectra also indicated the structural transformation due to Er and La substitution in BFO. On subsequent erbium doping, the intrinsic dielectric constant is found to decrease from 68 (for pure BFO) to 52 for BLEFO x = 0·05 to 43 for BLEFO x = 0·07 but increased to 89 for BLEFO x = 0·1 when compared to pure BFO. The increase in Er content resulted in the increase in spontaneous magnetization (0·1178 emu/g at 8T for BLEFO x = 0·1 ) due to collapse of spin cycloid structure. Ferroelectric remnant polarization of BLEFO x = 0·05 and BLEFO x = 0·07 decreases when compared to pure BFO while small remnant polarization (close to paraelectric behaviour) is evident for BLEFO x = 0·1 .

Bismuth ferrite (BFO) and La-substituted BFO with composition Bi1−xLaxFeO3 (x=0.05, 0.1 and 0.15) (BLFOx=0.05–0.15) ceramics were prepared using the solid state reaction route. A structural phase transition from rhombohedral phase to triclinic phase was observed for BLFOx=0.05–0.15 ceramics. Modulus spectroscopy reveals the deviation of dielectric behavior from ideal Debye characteristics and the dependence of conductivity on ion hopping in BFO and BLFOx=0.05–0.15 ceramics. The conductivity of the BFO ceramics decreases for La content of 5mol%, followed by a subsequent increase with 10 and 15mol% of lanthanum doping. The typical values of the activation energies at high temperature reveal the contribution of short range movement of doubly ionized oxygen vacancies to the conduction process in BFO and BLFOx=0.05 ceramics. Both short range and long range motion of oxygen vacancies are responsible for large conductivity in BLFOx=0.1 and 0.15 ceramics.

Single phase Bi0.9−xLa0.1NdxFeO3 (BLNFOx) (x=0.05, 0.07, and 0.1) multiferroic ceramics were prepared to study the effect of combine substitution of La and Nd in BiFeO3 (BFO). X-ray diffraction studies revealed phase transition from rhombohedral (R3c) to triclinic (P1) on substitution of 05 and 07 mol % of Nd and subsequent transition to monoclinic C2/c with 10 mol % of Nd along with 10 mol % of La. These structural phase transitions and weakening of long range ferroelectric order with increasing x are also confirmed from Raman spectra. The existence of ferroelectricity and the corresponding Curie temperature for all noncentrosymmetric composition were determined using differential thermal analysis. Small remnant magnetization of 0.067 emu/g is observed in (BLNFO)x=0.07 as a result of collapse of space modulated spin structure. For pure BFO dielectric anomaly was observed at 355 °C corresponding to Neel temperature. Due to coexistence of long range ferroelectric order and canted antiferromagnetic orders in (BLNFO)x=0.05 and 0.07 the magnetoelectric effects were observed below Neel temperature at 302 and 294 °C, respectively, near which magnetoelectric coupling is obvious.

Structural, electrical and magnetic properties of Bi0.9-xLa0.1ErxFeO3 (BLEFOx) (x = 0.05, 0.07, 0.1) polycrystalline ceramics prepared by solid solution route were studied. A phase transition from rhombohedral phase to monoclinic phase was observed for x=0.05-0.1 in (BLEFOx). We have measured phase transition temperatures both alpha-beta transition and low-Temperature (low-T) transitions in doped BiFeO3. The transition peak near to 835C corresponds to alpha to beta-phase transition of BiFeO3 were measured using diffential thermal analysis (DTA). Dielectric measurements shows the low-T transitions in BLEFOx (x = 0.05-0.1). Relatively high remanent magnetization of 0.1178emu/gm at 8T was observed in BLEFOx (x = 0.1).

The shape-memory effect is investigated in a number of solid solutions of PbMg1/3Nb2/3O3 (PMN) and PbTiO3 (PT), with and without doping by La3+. Three-point-bending experiments were conducted on thin bar-shaped specimens, thermally cycled through the martensitic phase transition. The maximum shape-memory strain (emax) was calculated, at various temperatures in the martensitic phase, from the radius of curvature of the pseudo-plastically bent specimen bars in the cooling segment of the shape-memory cycle. The relaxor character of each composition was determined from the shapes of the ferroelectric hysteresis loops, and from the permittivity data fitted to a modified Curie–Weiss law. Starting from the morphotropic-boundary composition of PMN/PT, namely 65/35, the relaxor character increases progressively as we move to the compositions 70/30 and 90/10. The same is the case when the 65/35 composition is doped with increasing amounts of La3+. It is observed that emax scales inversely with the relaxor character of the ferroelectric. An explanation of this is offered in terms of changes in the root-mean-square (rms) value of the remanent polarization, Pr. It is found that the remanent shape strain emax scales approximately as Pr2. This points to the central role played by internal electrostriction in determining the magnitude of the recoverable shape-memory strain in these ceramics. Further support for this interpretation is provided by the fact that, although these materials display very large thermal-expansion coefficients in the austenitic (or paraelectric) phase (attributable to the highly anharmonic nature of the interatomic potential), the thermal expansivity drops to very low values in the martensitic phase.