William C. Mahaney, Volli Kalm,
... fluvial depositional environment. The deposits of Middle Devonian Aruküla Stage were emplaced in a continental water basin ... the SEM microtextures on quartz grains from the Aruküla Stage should show mainly the effect of stream ...
Tópico(s): Paleontology and Stratigraphy of Fossils
2000 - Wiley | Boreas
In the Baltic Region the Aruküla Stage (Eifelian) is characterized by reddish brown cross-bedded sandstone interbedded with siltstone, clay, and domerite.In Estonia it is represented ...
Tópico(s): Linguistics and Cultural Studies
1994 - Estonian Academy Publishers | Proceedings of the Estonian Academy of Sciences Geology
... on scales found in the beds of the Aruküla Regional Stage of Siverskiy and Zaitsevo localities of ...
Tópico(s): Paleontology and Stratigraphy of Fossils
2018 - Pleiades Publishing | Paleontological Journal
Kati Tänavsuu‐Milkeviciene, Piret Plink‐Björklund,
... deltaic deposits of the Middle Devonian Kernave and Arukula formations were documented in cores and outcrops in ...
Tópico(s): Hydrocarbon exploration and reservoir analysis
2009 - Society for Sedimentary Geology | Journal of Sedimentary Research
Ravi Arukula, Apparao Thota, Chepuri R.K. Rao, Ramanuj Narayan, B. Sreedhar,
ABSTRACT New class of conducting polyurethanes (CPUs) containing oligoanilines, namely tetraaniline (TAni) or trianiline (TriAni), in the backbone have been synthesized and characterized by formal spectral techniques. The unique properties of these CPUs, viz., electronic conductivity and electrochemical activity arising from the presence of oligoaniline units have been evaluated. The basic polyurethane backbone is derived from toluene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate, ...
Tópico(s): Organic Electronics and Photovoltaics
2014 - Wiley | Journal of Applied Polymer Science
Gurunathan Thangavel, Ravi Arukula, Jin Suk Chung, Chepuri R.K. Rao,
This study describes the fabrication and characterization of castor oil-based waterborne polyurethane/polyaniline (COWPU/PAni) conducting polymer blend films. The COWPU synthesized from isophorone diisocyanate was reacted with castor oil to form prepolymers, which were chain extended by reacting it with N-methyldiethanolamine. Quaternization and self-emulsification including deionized water followed in COWPU dispersions. Also, COWPU/PAni hybrid dispersions were synthesized with 2, 4, and 6 wt% of ...
Tópico(s): Polydiacetylene-based materials and applications
2016 - Wiley | Polymers for Advanced Technologies
Himadri S. Karmakar, Ravi Arukula, Apparao Thota, Ramanuj Narayan, Chepuri R.K. Rao,
ABSTRACT We report the superior corrosion‐resistant properties of conducting polyurethane networks of polyaniline (PANI), poly‐ m ‐aminophenol (PmAP), and poly‐ o ‐anisidine (PoA) coated on mild steel panels. These networks were prepared by blending conducting polyanilines with isocyanate‐containing prepolyurethanes. Free‐standing polyurethane films were obtained after a moisture cure for several days to ensure complete reaction of the excess isocyanate. The films were electrochemically active with conductivity ...
Tópico(s): Advanced Sensor and Energy Harvesting Materials
2017 - Wiley | Journal of Applied Polymer Science
Ravi Arukula, Mohanraj Vinothkannan, Ae Rhan Kim, Dong Jin Yoo,
In this article, we report a wet reflux strategy for the synthesis of reduced graphene oxide (rGO)/polyaniline (PANI)/Pt-Pd composite, which was exploited as a potential anode catalyst with enhanced methanol oxidation capacity for direct methanol fuel cells (DMFCs). The construction of rGO/PANI/Pt-Pd involves two steps such as synthesis of PANI on GO and in-situ reduction of GO and metal precursors. The spherical shaped Pt-Pd particles with the average size of 3.5 nm are scattered throughout the surface ...
Tópico(s): Electrocatalysts for Energy Conversion
2018 - Elsevier BV | Journal of Alloys and Compounds
Apparao Thota, Karteek Boga, Ravi Arukula, Ramanuj Narayan, Chepuri R.K. Rao,
Schiff bases are small molecules possessing CN functional groups which are exploited for coordinating inorganic cations to form stable complexes which play the critical role in catalysis. Here we synthesized a new Schiff base molecule (SBM) by condensation of terephthalaldehyde and conjugated dianiline to study its electrical and electrochemical properties. This Schiff base molecule (SBM) can be oxidized with ammonium peroxodisulfate in presence of 1 M HCl solution into emeraldine base form (O-SBM). ...
Tópico(s): Organic Electronics and Photovoltaics
2018 - Elsevier BV | Synthetic Metals
Gurunathan Thangavel, Ravi Arukula,
A series of hyperbranched polyesters were incorporated by the chemical reaction of the dimethylolpropionic acid with trimethylolpropane, pentaerythritol, and glycerol as the core group. The castor oil-based fatty acids were also successfully prepared in order to examine the impact of the biopolyols on the thermo-mechanical characteristics of the hyperbranched waterborne polyurethane. The chemical structure of the polyols and the resulting polymer were characterized. Developing −OH functionality of ...
Tópico(s): Synthesis and properties of polymers
2018 - Elsevier BV | Polymer Degradation and Stability
Umesh S. Waware, Ravi Arukula, A.M.S. Hamouda, Peter Kasák,
Abstract We report the synthesis of high soluble poly(aniline-co-o-hydroxyaniline) copolymers with varying the amount of o-hydroxyaniline (20, 40, 60, and 80 %) and referred as PA-co-o-HA20, PA-co-o-HA40, PA-co-o-HA60, and PA-co-o-HA80 respectively. The chemical and structural composition of the polymers and copolymers were determined by XPS, UV–Vis, and FE-SEM analysis. Electrochemical studies of the as-prepared polymers showed two single-electron oxidations and two single-electron reductions reversibly ...
Tópico(s): Electrochemical sensors and biosensors
2019 - Springer Science+Business Media | Ionics
Deblina Maiti, Iqbal Ansari, Mohd Ashraf Rather, Arukula Deepa,
Abstract Wastewaters discharged from various coal-related activities deteriorate fresh water quality and inflict possibilities of groundwater contamination. Their characteristics mostly depend on the parent coal properties, though some of the pollutants are cyanide, thiocyanate, ammonia, phenol, heavy metals and suspended solids. This paper has reviewed the treatment techniques along with the characteristics of all such kinds of wastewater and also identified the challenges and future perspectives. ...
Tópico(s): Arsenic contamination and mitigation
2019 - Pergamon Press | Water Science & Technology
Abdul Hameed, Arukula Balakrishna, B. Srinivas, M. Chandrasekhar, Md. Shareefuddin, M. Narasimha Chary,
In this paper the studies on xMO-10Li2O-10Na2O–10K2O-(70-x)B2O3 [M=Mg, Sr and Ba] [x = 2, 4, 6, 8 and 10 mol%] glasses doped with manganese ions are reported. The physical and spectroscopic properties were investigated to know about the influence of the alkaline ions. The density values of all the glasses were found to increase with increasing alkaline earth oxide content while the values of molar volume were decreasing. The UV–VIS spectra of these glasses have shown single broad band which was assigned ...
Tópico(s): Lanthanide and Transition Metal Complexes
2021 - Elsevier BV | Optik
Karteek Boga, Ramyakrishna Pothu, Ravi Arukula, Rajender Boddula, Sashivinay Kumar Gaddam,
Abstract Research on corrosion-resistant polymer coatings has attracted scientists in both academia and industry to prevent corrosion-related damage in modern industrial equipment and to extend the working life of industrial metallic surfaces. To achieve realistic applications, diverse methodologies have been designed to magnify the anticorrosion efficiency of these coatings. The current review describes the conventional and advanced methods utilized for the synthesis of corrosion-resistant polymer ...
Tópico(s): Fuel Cells and Related Materials
2021 - De Gruyter | Corrosion Reviews
S. Anilkumar, Arukula Deepa, K. Narayani, A. K. Rekha, P. V. Achuthan, G. Krishnamachari, D.N. Sharma,
Tópico(s): Advanced X-ray and CT Imaging
2007 - Springer Science+Business Media | Journal of Radioanalytical and Nuclear Chemistry
Johanna-Iisebel Järvelill, A Kleesment, Anto Raukas,
... originated mainly from the Devonian sandstones of the Aruküla and Narva regional stages, amphiboles and pyroxenes mainly ...
Tópico(s): Geochemistry and Elemental Analysis
2015 - Geological Society of Finland | Bulletin of the Geological Society of Finland
Apparao Thota, Ravi Arukula, Ramanuj Narayan, Chepuri R.K. Rao, K. V. S. N. Raju,
Phosphoric acid doped co-polyanilines of substituted anilines and dianiline give conductivities up to 9.25 × 10 −2 S cm −1 , specific capacitances on a stainless steel capacitor of 110–176.76 F g −1 at 0.5 A g −1 and have high corrosion resistance on a steel surface.
Tópico(s): Organic Electronics and Photovoltaics
2015 - Royal Society of Chemistry | RSC Advances
Arukula Deepa, Prem Prakash, Brijesh Kumar Mishra,
In the present study, the performance of biochar-based filtration bed was assessed to enhance the removal efficiency of Cr(VI), from the pre-treated synthetic tannery wastewater. The pre-treatment of wastewater was carried out with aluminium formate (AF) as a coagulant and 80% Cr(VI) removal was observed which might be due to the formation of carboxylic complexation reaction. The purity of coagulant and the sludge components were validated with XRD analysis and the results revealed the formation ...
Tópico(s): Heavy metals in environment
2019 - Taylor & Francis | Environmental Technology
Arukula Balakrishna, B. Srikantha Chary, K. Chandra Sekhar, Samdani, Md. Shareefuddin,
Tópico(s): Nuclear materials and radiation effects
2022 - Springer Science+Business Media | The European Physical Journal Plus
... of the Leningrad Region, northwestern Russia, within the Aruküla and Burtnieki regional stages, Givetian, Middle Devonian.The ...
Tópico(s): Fish Biology and Ecology Studies
2014 - Estonian Academy Publishers | Proceedings of the Estonian Academy of Sciences Geology
Ravi Arukula, Ramanuj Narayan, B. Sreedhar, Chepuri R.K. Rao,
New series of electrochemically active conducting polyurethanes (CPU) have been prepared using tetraaniline as conducting unit with IPDI-PTMG as urethane prepolymer segment. These films are robust and formed as a consequence of moisture curing of excess isocyanate. The films are novel in the sense that the conductivity is found to be in the higher side of the order of 10−3 S/cm and the tetraaniline segments are electrochemically oxidizable and/or reducible. The formed films have been subjected for ...
Tópico(s): Corrosion Behavior and Inhibition
2016 - Elsevier BV | Progress in Organic Coatings
Arukula Deepa, Astha Singh, Aakansha Singh, Brijesh Kumar Mishra,
Tópico(s): Environmental remediation with nanomaterials
2020 - Springer Science+Business Media | Environmental Science and Pollution Research
B. Srikantha Chary, Arukula Balakrishna, B. Srinivas, K. Chandra Sekhar, Abdul Hameed, Md. Shareefuddin,
The present manuscript deals with the preparation and structural studies of BaF2–TeO2 – Li2B4O7–CuO glasses. The glasses were made using the melt quenching procedure, and their properties were examined utilizing the density, absorption, FTIR, Raman, and EPR spectra. The lack of strong peaks in the XRD spectra provides evidence that the phase is non-crystalline. The samples' densities went up but their molar volumes went down. The transition between 2B1g and 2B2g is responsible for a broad absorption ...
Tópico(s): Radiation Shielding Materials Analysis
2023 - Elsevier BV | Optical Materials
Camila Zequine, Sanket Bhoyate, Felipe M. Souza, Ravi Arukula, P.K. Kahol, Ram K. Gupta,
Owing to an increase in energy demand, excessive utilization of fossil fuels, and growing appeal for environmental protection, it is vital to develop cost-effective and highly efficient materials for energy storage and conversion devices. Currently, supercapacitors are considered to be advanced electrochemical energy storage devices due to their speedy charge-discharge, outstanding electrochemical stability, and high-power density. In recent decades, extensive studies have been performed to understand ...
Tópico(s): Advanced Sensor and Energy Harvesting Materials
2020 - American Chemical Society | ACS symposium series
... Red Sandstone facies of the late Middle Devonian Aruküla-Burtnieki complex, several discontinuity surfaces are present. The ...
Tópico(s): Geological formations and processes
2001 - Taylor & Francis | GFF
Arukula Deepa, Sonalika Sonal, Brijesh Kumar Mishra,
This paper aims to scrutinize the comparative performance of hybrid biofilter via column mode to boost the reduction rate of Cr (VI) and organic pollutants in various pre-treated tannery wastewater. The pre-treated water through aluminium formate, aluminium sulphate, and ferric chloride were passed through two divergent biofilter medium discretely with (i) immobilized sodium alginate microbial beads (Im/S.AM.B) and (ii) co-immobilized microbial biochar beads (Co-im/B.M.B). Biosorption efficiency of the ...
Tópico(s): Constructed Wetlands for Wastewater Treatment
2022 - Elsevier BV | Journal of Water Process Engineering
Swathy Krishna Bhaskaran, Karteek Boga, Ravi Arukula, Sashivinay Kumar Gaddam,
Tópico(s): biodegradable polymer synthesis and properties
2023 - Springer Science+Business Media | Journal of Polymer Research
D Sakthilatha, Arukula Deepa, R. Rajavel,
Six novel mononuclear Schiff base metal complexes of the type [ML1L2]X and [ML1L2X], where M = Cu(II), Ni(II), Co(II), Mn(II), Zn(II), and VO(IV) have been synthesized by condensation of 1-(1-(pyridine-2-yl)ethylidene)thiosemicarbazide (L1) and 1-(1-(2,4-dihydroxyphenyl)ethylidene)thiosemicarbazide (L2) in the presence of divalent metal salts. The synthesized ligands and complexes were structurally characterized on the basis of elemental analysis, IR, UV-visible, 1H NMR spectroscopy, molar conductance, ...
Tópico(s): Crystal structures of chemical compounds
2014 - Marcel Dekker | Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry
Ravi Arukula, Chepuri R.K. Rao, Ramanuj Narayan, B. Sreedhar,
For the first time we report a novel hybrid polyurethane synthesized from tetraaniline-diol (TAni-(OH)2) and hexamethylene diisocyanate (HMDI) with pendant tetraaniline units on the back bone. The striking property of this unprecedented polyurethane is its electrochemical sensing of ascorbic acid and self assembly into core–shell type microstructures (microcapsules) in presence of aqueous acetic acid/n-octane interface. These microcapsules exhibited a wide range of pH responses in their absorption ...
Tópico(s): Electrochemical sensors and biosensors
2015 - Elsevier BV | Polymer
Michael J. Newman, Jan L. den Blaauwen, Carole J. Burrow,
... from isolated scales from the upper Narva and Aruküla Regional Stages of the east Baltic region. The ...
Tópico(s): Fish Ecology and Management Studies
2020 - Zoological Society of London | Scottish Journal of Geology