Nanohybrid material of Co–TiO2 and optical performance on methylene blue dye under visible light illumination Sathish Mohan Botsa, Seetharam P, I. Manga Raju, Suresh P, G. Satyanarayana, Sangaraju Sambasivam, Susmitha Uppugalla, Tejeswararao D Hybrid Advances, 2022 The present study explores the sonochemical route for preparing Cobalt doped Titania (CTN) nanoparticles (NPs). As-prepared CTN NPs were characterized by analytical instruments such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Brunauer–Emmett–Teller (BET), UV–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS), and Fourier Transform Infrared Spectroscopy (FTIR) to study their structural, optical and morphological properties. The characterisation results confirmed the pure phase of prepared CTN NPs by doping Cobalt into TiO2 nanoparticles via a sonochemical route. Further studies were conducted to characterise CTN NPs and investigated their photocatalytic performance over the decolourisation of model dye pollutant Methylene blue (MB) under visible light illumination. Cobalt doping into TiO2 NPs has led to the reduced bandgap, which possesses excellent pore area (56 m2/g), thus CTN NPs acts as a benign visible-light-driven photocatalyst over MB dye that completely degraded (99%) in 75 min without oxidising agents. The photodegradation results of CTN NPs were compared with previous reports of other metal-doped TiO2 nanoparticles and found that CTN NPs is the best photocatalyst for the degradation of MB dye.
A Study on Development of Pollution Index Models and Multivariate Statistical Analysis for Heavy Metals in the Soils of APIIC, Visakhapatnam G. V. Satyanarayana, T. Byragi Reddy, R. S. S. Srikanth Vemuri, K. Suryanarayana Rao, Manoj Kumar Karnena Nature Environment and Pollution Technology, 2021 Soil pollution is a worldwide problem caused by both natural and anthropogenic activities. This has resulted in health and physiological problems to both plants and animals. This study investigated heavy metals in soils within the immediate vicinity. Soils from Seven APIIC zones in Visakhapatnam were collected and analysed for physicochemical characteristics and heavy metals. The data obtained were subjected to the pollution index model and multivariate statistical analysis. The data obtained showed that the soils are rich in zinc, and heavy metals are above trace level with a minor positively skewed distribution. The analysis of pollution index, geoaccumulation index and ecological risk factors in soils in all the locations showed that they are mainly contaminated and polluted by Cd followed by Zn. The mean heavy metal concentrations around APIIC can be arranged in increasing order as Cr < Co < Pb < Cu < Cd < Zn. Element pairs such as Zn-Pb, Zn-Cu, Zn-Cd, Pb-Cu, Pb-Cd, Cu-Cr, Cd-Co and CrCo showed strong positive correlation coefficient “r” indicating their association in the study area. The observed concentrations of heavy metals revealed that soil contamination has been increasing and measures must be taken to ensure the adoption of more environment-friendly practices.
Structural, electrical, and magnetic properties of Co-substituted Ni1- xCo xFe2O4 (x = 0.1, 0.2, and 0.3) nanocrystalline ferrites G. Satyanarayana, K. Vijaya Babu, G. Nageswara Rao Ferroelectrics, 2021 Nanocrystalline ferrites are interesting materials due to their rich physical and electromagnetic properties. In the present work, Ni1-xCoxFe2O4 (x = 0.1, 0.2, and 0.3) nanocrystalline ferrites have been synthesized by solgel auto-combustion method and their microstructural, magnetic, and dielectric properties have been synthesized. The structural properties of synthesized ferrites are determined by using X-ray powder diffraction, scanning electron microscope, and Fourier transform infrared spectroscopy. The cation distribution obtained from X-ray diffraction shows that cobalt occupies only tetrahedral site in spinel lattice. The lattice constant of nickel ferrite increases with the increase in cobalt content. The structural parameters like bond lengths and tetrahedral and octahedral edges have been varied by cobalt substitution. The microstructural study carried out by using SEM technique showed that the average grain size increased with cobalt concentration. The initial permeability (μi) increased with increasing cobalt concentration. The observed g-value from ESR is approximately equal to standard value. From hysteresis curve, the saturation magnetization (Ms), coercivity (Hc), and magnetic moment (μB) are obtained as a function of cobalt concentration.
Potentiometric Studies on Bioactive Material Species of Ternary Complexes P. Seetharam, M. Balakrishna, B. Sathish Mohan, G. Satyanarayana, B. B. V. Sailaja Russian Journal of General Chemistry, 2020 Complexation of essential metal ions with glycylglycine and histamine in cetyltrimethylammonium bromide (CTAB) has been presented in this study, which targets insight in the distribution of species, effect of surfactants on stability constants of ternary complexes, and effect of concentration of alkali, acids, ligands, and metal ions on the stability constants. The studied complexes are MLXH2, ML2XH2, and MLX2H3. The advanced principles of mathematics and fuzzy logic have been employed to correlate chemical problems, known as chemo metrics. A potentiometer has been used for analysis, and the results obtained have been processed through gran plot method, SCPHD used for best fit chemical model. MINIQUAD75 has been used for refinement of the results.
Influence of chromium substitution on structural, electrical, and magnetic properties of Ni-Zn-Cu ferrites G. Satyanarayana, G. Nageswara Rao, K. Vijaya Babu, G.V. Santosh Kumar, G. Dinesh Reddy Acta Physica Polonica A, 2020 In this work, Ni0.5Zn0.3Cu0.2Fe2-xCrxO4 (x = 0.02, 0.04, 0.06, 0.08, and 0.1) ferrites are synthesized by sol-gel method, and study how relevant properties of the samples are modified accordingly. The structural, morphological, magnetic, and electrical features of the ferrites are evaluated by X-ray diffraction, scanning electron microscope, the Fourier transmission infrared spectra, vibrating sample magnetometer, electron spin resonance, and network analyser. The lattice constant decreases with chromium concentration and the decrease in lattice constant is attributed to the smaller ionic radius of chromium compared to iron. Distribution of metal cations in the spinel structure, estimated from X-ray diffraction data, show that along with Ni 2+ ions, most of the Zn 2+ and Cu 2+ ions additionally occupy the octahedral B sites. The Fourier transform infrared spectra revealed two prominent frequency bands in the wave number range 400-600 cm -1 which confirm the cubic spinel structure. Magnetic properties, such as initial permeability, saturation magnetization, and coercivity have been investigated at room temperature. The frequency dependent dielectric constant is observed to decrease with the increased chromium concentration. This behaviour has been explained in accordance with the Koops phenomenological theory.
Effect of Cr 3+ Substitution on the Structural, Electrical and Magnetic Properties of Ni 0.7 Zn 0.2 Cu 0.1 Fe 2−x Cr x O 4 Ferrites G. Satyanarayana, G. Nageswara Rao, K. Vijaya Babu, G. V. Santosh Kumar, G. Dinesh Reddy Journal of the Korean Physical Society, 2019 In this work, Ni0.7Zn0.2Cu0.1Fe2−xCrxO4 (x = 0.02, 0.04, 0.06, 0.08 and 0.1) ferrites were synthesized by using the solid state reaction method and how relevant properties of the samples were modified accordingly. The structural, morphological, magnetic and electrical features of the ferrites were evaluated by using X-ray diffraction, scanning electron microscopy, Fourier transmission infrared (FTIR) spectra, vibrating sample magnetometry, electron spin resonance and network analyser. The lattice constant decreases with increasing chromium concentration and the decrease in the lattice constant is attributed to the ionic radius of chromium being smaller than that of iron. The distribution of metal cations in the spinel structure was estimated from the X-ray diffraction data and showed that along with Ni2+ ions, most of the Zn2+ and the Cu2+ ions additionally occupied the octahedral [B] sites. The FTIR spectra revealed two prominent frequency bands in the wave number range 400–600 cm−1 which confirm the cubic spinel structure. The magnetic properties, such as the initial permeability, saturation magnetization and coercivity, were investigated at room temperature. The frequency-dependent dielectric constant was observed to decrease with increasing chromium concentration. This behavior was using Koops phenomenological theory.
Application of geoelectrical method for interpretation of geohydrological conditions around Rajahmundry, A.P Journal of the Geological Society of India, 2004
Suitability of coastal magnetite for ferrite preparation Current Science, 2003
K-electron capture probabilities in161Ho G. Sree Krishna Murty, N. V. S. Vara Prasad, M. V. S. Chandrasedhar Rao, M. Ravi Kumar, G. Satyanarayana, D. L. Sastry Il Nuovo Cimento A Series 11, 1993
K-electron capture probability in 167Tm G Sree Krishna Murty, M V S Chandrasekhar Rao, K Radha Krishna, S Bhuloka Reddy, G Satyanarayana, P V Ramana Rao, D L Sastry, S N Chintalapudi Journal of Physics G Nuclear and Particle Physics, 1990
Electron Capture Probabilities in105Ag M. V. S. Chandrasekhar Rao, G. Sree Krishna Murty, K. Radha Krishna, S. Bhuloka Reddy, G. Satyanarayana, C. V. Raghavaiah, D. L. Sastry, S. N. Chintalapudi Zeitschrift Fur Physik A Atomic Nuclei, 1990
Distribution and factor analysis of benthic foraminifera in Nizampatnam Bay, east coast of India Journal Geological Society of India, 1990
Anomalous conversion of 127 keV (E3) transition in134Cs M. V. S. Chandrasekhar Rao, N. Venkateswara Rao, S. Bhuloka Reddy, G. Satyanarayana, D. L. Sastry, M. R. Iyer, S. G. Sahasrabhude Zeitschrift Fur Physik A Atomic Nuclei, 1988
Decay of61Cu G. Satyanarayana, N. Venkateswara Rao, G. S. Sri Krishna, M. V. S. Chandrasekhar Rao, S. Bhuloka Reddy, D. L. Sastry, S. N. Chinthalapudi, V. V. Rao Il Nuovo Cimento A Series 11, 1988
Implications of daily thermal variations in the ventilation and indoor CO 2 levels in the karstic system of the Altamira Cave C Sainz, I Morales, D Rábago, S Celaya, A Fernández, I Fuente, ... Environmental Science: Atmospheres , 2026 2026
The RADIANT Project: Preliminary Approaches to Radon Assessment and Monitoring in Historic Heritage Buildings I Sicilia, B Frutos Vázquez, C Sáinz, L Quindós, J García Rubiano, ... 2025
Evaluation of commercial facemasks to reduce the radioactive dose of radon daughters I Gutiérrez-Álvarez, SC González, IF Merino, LS Quindós, CS Fernández Journal of Industrial Textiles 54, 15280837241247342 , 2024 2024
Investigation of the performance of various low-cost radon monitors under variable environmental conditions D Rábago, E Fernández, S Celaya, I Fuente, A Fernández, J Quindós, ... Sensors 24 (6), 1836 , 2024 2024 Citations: 19
Control of radon flux of an inactive Uranium Mill Facility in Spain I Fuente, C Sainz, L Quindós, D Rábago, I Gutiérrez, A Fernández, ... Atmosphere 14 (10), 1536 , 2023 2023 Citations: 3
Comparison of a lumped-parameter and a distributed-parameter radon transport models adapted to an experimental radon accumulation chamber within the frame of the Spanish RADSIM … L Font, B Frutos Vázquez, I Sicilia, H Alonso, M García-Talavera, P Martel, ... 2023
Monitoring of the spatial and temporal variation of radon in an inhabited house, subjected to an underground source of radon from a well. Case study of Valsequillo in Gran … JT Santana, H Alonso, L Font, B Frutos Vázquez, M García-Talavera, ... 2023
Parameters monitorization in a Pilot House to provide data for indoor radon simulation and prediction purposes. D Rábago, JG Rubiano, H Alonso, L Font, B Frutos Vázquez, ... 2023
Overview and new advances of RADSIM, a research project for the generation and validation of numerical models for the prediction of radon entry into buildings based on a … JG Rubiano, H Alonso, L Font, B Frutos Vázquez, M García-Talavera, ... 2023
Reliable radon flux observations for supporting Radiation Protection and GreenHouse Gase reduction strategies C Grossi, S Chambers, D Rabago, L Quindos, R Curcoll, V Morosh, ... EGU General Assembly Conference Abstracts, EGU-5816 , 2023 2023
Characterizing the automatic radon flux Transfer Standard system Autoflux : laboratory calibration and field experiments C Grossi, D Rabago, S Chambers, C Sáinz, R Curcoll, PPS Otáhal, ... Atmospheric Measurement Techniques Discussions 2023, 1-22 , 2023 2023 Citations: 10
Metrology infrastructure for radon metrology at the environmental level A Röttger, S Röttger, D Rábago Gómez, LS Quindós Poncela, ... 2023 Citations: 7
Modelo CFD con validación de campo para el estudio de los alcances de efectividad de técnicas de mitigación de radón por despresurización= CFD model with field validation for … I Sicilia, B Frutos, C Alonso, F Martín-Consuegra, F de-Frutos, I Oteiza, ... Anales de Edificación 8 (3), 47-53 , 2022 2022
BEYOND THE STATE OF ART: NEW METROLOGY INFRASTRUCTURE FOR RADON MEASUREMENTS AT THE ENVIRONMENTAL LEVEL A Röttger, S Röttger, D Rábago, L Quindós, K Woloszczuk, M Norenberg, ... Dubrovnik 23 , 2022 2022
On the use of numerical models to predict/mitigate indoor radon levels in highly contaminated areas L Font, H Alonso, B Frutos Vázquez, J García Rubiano, M García-Talavera, ... 2022
Definition and sensitivity analysis of a CFD model for the study of radon immission in buildings B Frutos, I Sicilia, JG Rubiano, H Alonso, L Font, V Moreno, C Sainz, ... INVITED TALKS, 182 , 2022 2022
Application of a mathematical model to an artificial aquifer under different recharge/discharge conditions using 222Rn as a tracer S Celaya, I Fuente, D Rábago, L Quindós, C Sainz Groundwater for Sustainable Development 17, 100753 , 2022 2022 Citations: 3
Intercomparison of radon flux monitors at low and at high radium content areas under field conditions D Rábago, L Quindós, A Vargas, C Sainz, I Radulescu, MR Ioan, ... International journal of environmental research and public health 19 (7), 4213 , 2022 2022 Citations: 25
CFD model with field validation applied to the study of the pressure ranges for radon mitigation depressurization techniques I Sicilia, B Frutos, C Alonso, F Martín-Consuegra, F de Frutos, ... 2022
Use of Radon and CO 2 for the Identification and Analysis of Short-Term Fluctuations in the Ventilation of the Polychrome Room Inside the Altamira Cave C Sainz, J Fábrega, D Rábago, S Celaya, A Fernandez, I Fuente, ... International Journal of Environmental Research and Public Health 19 (6), 3662 , 2022 2022 Citations: 13
MOST CITED SCHOLAR PUBLICATIONS
A new kind of natural radioactivity HJ Rose, GA Jones Nature 307 (5948), 245-247 , 1984 1984 Citations: 977
Natural radioactivity in Spanish soils LS Quindos, PL Fernandez, J Soto, C Rodenas, J Gomez Health physics 66 (2), 194-200 , 1994 1994 Citations: 271
Conversion factors for external gamma dose derived from natural radionuclides in soils LS Quindos, PL Fernandez, C Rodenas, J Gomez-Arozamena, J Arteche Journal of environmental radioactivity 71 (2), 139-145 , 2004 2004 Citations: 108
National survey on indoor radon in Spain LS Quindós, PL Fernández, J Soto Environment International 17 (5), 449-453 , 1991 1991 Citations: 93
Comparative risk assessment of residential radon exposures in two radon-prone areas, Ştei (Romania) and Torrelodones (Spain) C Sainz, A Dinu, T Dicu, K Szacsvai, C Cosma, LS Quindós Science of the Total Environment 407 (15), 4452-4460 , 2009 2009 Citations: 92
Building materials as source of exposure in houses LS Quindos, PL Fernandez, J Soto Indoor Air 87 (2), 365 , 1987 1987 Citations: 81
Natural ventilation of the paintings room in the Altamira cave PL Fernández, I Gutierrez, LS Quindós, J Soto, E Villar Nature 321 (6070), 586-588 , 1986 1986 Citations: 77
Radioactivity in Spanish spas J Soto, PL Fernandez, LS Quindos, J Gomez-Arozamena Science of the total environment 162 (2-3), 187-192 , 1995 1995 Citations: 73
Analysis of the main factors affecting the evaluation of the radon dose in workplaces: the case of tourist caves C Sainz, LS Quindós, I Fuente, J Nicolás, L Quindós Journal of Hazardous Materials 145 (3), 368-371 , 2007 2007 Citations: 66
Residential radon and cancer mortality in Galicia, Spain G López-Abente, O Núñez, P Fernández-Navarro, JM Barros-Dios, ... Science of the Total Environment 610, 1125-1132 , 2018 2018 Citations: 64
Study of the environmental variables affecting the natural preservation of the Altamira Cave paintings located at Santillana del Mar, Spain LS Quindos, A Bonet, N Diaz-Caneja, PL Fernandez, I Gutierrez, ... Atmospheric Environment (1967) 21 (3), 551-560 , 1987 1987 Citations: 58
Ambient temperature variations in the hall of paintings of Altamira cave due to the presence of visitors E Villar, A Bonet, B Diaz-Caneja, PL Fernandez, I Gutierrez, LS Quindos, ... Cave Science 11 (2), 99-104 , 1984 1984 Citations: 57
7Be concentrations in air, rain water and soil in Cantabria (Spain) C Ródenas, J Gómez, LS Quindós, PL Fernández, J Soto Applied Radiation and Isotopes 48 (4), 545-548 , 1997 1997 Citations: 55
Continuous monitoring of radon gas as a tool to understand air dynamics in the cave of Altamira (Cantabria, Spain) C Sainz, D Rábago, S Celaya, E Fernández, J Quindós, L Quindós, ... Science of the Total Environment 624, 416-423 , 2018 2018 Citations: 52
Radiation exposure levels in Altamira Cave PL Fernandez, LS Quindos, J Soto, E Villar Health Phys.;(United Kingdom) 46 (2) , 1984 1984 Citations: 42
Radón: un gas radiactivo de origen natural en su casa LS Quindós Consejo de Seguridad Nuclear , 2002 2002 Citations: 40
Indoor radon in a Spanish region with different gamma exposure levels LS Quindós, PL Fernández, C Sainz, I Fuente, J Nicolás, L Quindós, ... Journal of Environmental Radioactivity 99 (10), 1544-1547 , 2008 2008 Citations: 36
226 Ra and 222 Rn in Natural Waters in Two Typical Locations in Spain J Soto, LS Quindos, N Diaz-Caneja, I Gutierrez, PL Fernández Radiation Protection Dosimetry 24 (1-4), 109-111 , 1988 1988 Citations: 35
Influence of visitors on carbon concentrations in Altamira Cave E Villar, PL Fernandez, I Gutierrez, LS Quindós, J Soto Cave Science 13 (1), 21-23 , 1986 1986 Citations: 35
Performance of radon monitors in a purpose-built radon chamber M Fuente, D Rabago, S Herrera, L Quindos, I Fuente, M Foley, C Sainz Journal of Radiological Protection 38 (3), 1111-1127 , 2018 2018 Citations: 34
