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Manikandan A, Durka M, Antony SA. Hibiscus rosa-sinensis Leaf Extracted Green Methods, Magneto-Optical and Catalytic Properties of Spinel CuFe2O4 Nano- and Microstructures. J Inorg Organomet Polym Mater 2015. [DOI: 10.1007/s10904-015-0203-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Manikandan A, Hema E, Durka M, Amutha Selvi M, Alagesan T, Arul Antony S. Mn2+ Doped NiS (Mn x Ni1−x S: x = 0.0, 0.3 and 0.5) Nanocrystals: Structural, Morphological, Opto-magnetic and Photocatalytic Properties. J Inorg Organomet Polym Mater 2015. [DOI: 10.1007/s10904-014-0163-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Manikandan A, Durka M, Antony SA. Magnetically Recyclable Spinel Mn xZn 1–xFe 2O 4 (0.0 ≤ x ≤ 0.5) Nano-Photocatalysts. ACTA ACUST UNITED AC 2015. [DOI: 10.1166/asem.2015.1654] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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104
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Manikandan A, Vijaya JJ, Mary JA, Kennedy LJ, Dinesh A. Structural, optical and magnetic properties of Fe3O4 nanoparticles prepared by a facile microwave combustion method. J IND ENG CHEM 2014. [DOI: 10.1016/j.jiec.2013.09.035] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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105
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Manikandan A, Vijaya JJ, Narayanan S, Kennedy LJ. Comparative investigation of structural, optical properties and dye-sensitized solar cell applications of ZnO nanostructures. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:2507-2514. [PMID: 24745255 DOI: 10.1166/jnn.2014.8499] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dye-sensitized solar cells (DSSCs) based on ZnO nanostructures with two different morphologies, such as nanowires (ZNWs) and nanoparticles (ZNPs), were synthesized by microwave combustion (MCM) and conventional combustion (CCM) method. The obtained ZnO nanostructures were characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy. The XRD results confirmed the formation of hexagonal wurtzite ZnO. The crystallite size of the ZnO nanostructures was calculated using Sherrer's formula. The formation of ZNWs and ZNPs was confirmed by HR-SEM and HR-TEM. The optical absorption and PL emissions were determined by DRS and PL spectra respectively. ZnO nanostructures with band gap energies of 3.36 eV (MCM) and 3.25 eV (CCM) were obtained. The dye-sensitized ZnO nanowire arrays exhibit much stronger optical absorption as compared with ZnO nanoparticle arrays, suggesting that the larger surface area improves light harvesting. The dye-sensitized solar cell based on the optimized ZnO nanowires array reaches a conversion efficiency of 1.73%, which is higher than that obtained from ZnO nanoparticles (0.69%) under the light radiation of 1000 W/m2. As-prepared ZNWs have potential applications in fabricating next generation nanodevices.
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Manikandan A, Vijaya JJ, Ragupathi C, Kennedy LJ. Optical properties and dye-sensitized solar cell applications of ZnO nanostructures prepared by microwave combustion synthesis. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:2584-2590. [PMID: 24745267 DOI: 10.1166/jnn.2014.8515] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the present study, ZnO nanoparticles (ZNPs) and nanoflakes (ZNFs) were prepared by conventional combustion method and microwave combustion method, respectively. The structural phase and morphology were investigated by using X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM) and high resolution transmission electron microscopy (HR-TEM). The crystallite size was calculated using Scherrer formula, and it lies in the range of 20-21 nm for ZNFs and 23-28 nm for ZNPs. The elemental analysis was investigated by energy dispersive X-ray analysis (EDX). Also, absorbance and emission spectra were measured by using diffuse reflectance (DRS) and photoluminescence (PL) studies. The band gap was measured using Kubelka-Munk model and it shows 3.47 eV for ZNFs and 3.26 eV for ZNPs. A fill factor (FF) of 0.57, short-circuit current (J(sc)) of 8.02 mA/cm2, open-circuit voltage (V(oc)) of 0.70 V and an overall light to electricity conversion efficiency (eta) of 1.62% were obtained from the dye-sensitized solar cell (DSSCs) based on ZNFs.
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Manikandan A. Urea Intercalated Biochar–a Slow Release Fertilizer Production and Characterisation. ACTA ACUST UNITED AC 2013. [DOI: 10.17485/ijst/2013/v6i12.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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108
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Ragupathi C, Vijaya JJ, Manikandan A, Kennedy LJ. Phytosynthesis of nanoscale ZnAl2O4 by using Sesamum (Sesamum indicum L.) optical and catalytic properties. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:8298-8306. [PMID: 24266227 DOI: 10.1166/jnn.2013.7922] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
There is a growing concern for the development of alternative environment friendly sustainable methods for the preparation of nanomaterials. Phytosynthesis of nano zinc aluminate by a microwave method using high purity metal nitrates and Sesamum (Sesamum indicum L.) extract is reported in this work. Sesamum (Sesamum indicum L.) extract simplifies the process and provides an alternative method for a simple and economical way of synthesis of nano zinc aluminate. It is also prepared by conventional method for comparison purpose. The obtained nanomaterials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), nitrogen adsorption/desorption isotherms, diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The formation of pure zinc aluminate phase is confirmed by XRD and FT-IR. The change in morphology from nanoplates to nanoporous sheets from the conventional to microwave heating method is clearly shown by HR-SEM. UV-Visible diffuse reflectance spectroscopy (DRS) studies revealed the band gap energy of ZnAl2O4 nanoplates and nanoporous sheets as 4.0 to 4.2 eV respectively. Photoluminescence (PL) emissions are centered at around 480, 519 and 545 nm, respectively. ZnAl2O4 nanoporous sheets prepared by microwave method showed better catalytic activity for the oxidation benzyl alcohol (90%) than ZnAl2O4 nanoplates prepared by conventional method (51%).
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Sarkar B, Manikandan A, Nandy M, Gossman MS, Sureka CS, Ray A, Sujatha N. A mathematical approach to beam matching. Br J Radiol 2013; 86:20130238. [PMID: 23995874 DOI: 10.1259/bjr.20130238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE This report provides the mathematical commissioning instructions for the evaluation of beam matching between two different linear accelerators. METHODS Test packages were first obtained including an open beam profile, a wedge beam profile and a depth-dose curve, each from a 10×10 cm(2) beam. From these plots, a spatial error (SE) and a percentage dose error were introduced to form new plots. These three test package curves and the associated error curves were then differentiated in space with respect to dose for a first and second derivative to determine the slope and curvature of each data set. The derivatives, also known as bandwidths, were analysed to determine the level of acceptability for the beam matching test described in this study. RESULTS The open and wedged beam profiles and depth-dose curve in the build-up region were determined to match within 1% dose error and 1-mm SE at 71.4% and 70.8% for of all points, respectively. For the depth-dose analysis specifically, beam matching was achieved for 96.8% of all points at 1%/1 mm beyond the depth of maximum dose. CONCLUSION To quantify the beam matching procedure in any clinic, the user needs to merely generate test packages from their reference linear accelerator. It then follows that if the bandwidths are smooth and continuous across the profile and depth, there is greater likelihood of beam matching. Differentiated spatial and percentage variation analysis is appropriate, ideal and accurate for this commissioning process. ADVANCES IN KNOWLEDGE We report a mathematically rigorous formulation for the qualitative evaluation of beam matching between linear accelerators.
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Manikandan A, Selvam NCS, Kennedy LJ, Kumar RT, Vijaya JJ. Structural and optical properties of novel ZrO2 nanostructures by microwave and solution combustion method. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:2595-2603. [PMID: 23763134 DOI: 10.1166/jnn.2013.7357] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Nanosized zirconium oxide (ZrO2) powders were synthesized by the microwave combustion synthesis (MCS) using glycine as the fuel without using any template, catalyst or surfactant. For the purpose of comparison, it was also prepared using solution combustion synthesis (SCS). The as-synthesized ZrO2 was characterized by X-ray powder diffraction (XRD), Fourier Transform infrared spectra (FT-IR), high resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The XRD results confirmed the formation of cubic phase ZrO2. FT-IR was used to investigate the adsorption of water and CO2 on ZrO2 surface and confirm the formation of Zr-O phase. The formation of ZrO2 nanospheres was confirmed by HR-SEM and TEM and their possible formation mechanisms were also proposed. The optical absorption and photoluminescence emissions were determined by DRS and PL spectra respectively.
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Manikandan A, Vijaya JJ, Kennedy LJ. Structural, optical and magnetic properties of porous alpha-Fe2O3 nanostructures prepared by rapid combustion method. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:2986-2992. [PMID: 23763190 DOI: 10.1166/jnn.2013.7402] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Porous iron oxide (alpha-Fe2O3) nanoparticles were synthesized by the microwave combustion method (MCM) using urea as the fuel. For the purpose of comparison, it was also prepared using the conventional combustion method (CCM). The as-synthesized porous alpha-Fe2O3 nanoparticles were characterized by X-ray powder diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET) analysis and vibrating sample magnetometer (VSM) analysis. The XRD results confirmed the formation of rhombohedral alpha-Fe2O3 phase. The formation of alpha-Fe2O3 nanoparticles was confirmed by HR-SEM and HR-TEM, and their possible formation mechanisms were also proposed. The optical absorption and the band gap were determined by DRS spectra. The surface area was derived from the nitrogen adsorption-desorption isotherms using BET analysis. The magnetic properties of the synthesized alpha-Fe2O3 were investigated with vibrating sample magnetometer (VSM) and their hysteresis loops were obtained. Both the prepared samples show ferromagnetic behavior with hysteresis curve at room temperature. The relatively high saturation magnetization (65.23 emu/g) of alpha-Fe2O3-MCM suggests that this method is suitable for preparing high-quality nanocrystalline magnetic alpha-Fe2O3 for practical applications.
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Manikandan A, Judith Vijaya J, John Kennedy L, Bououdina M. Structural, optical and magnetic properties of Zn1−xCuxFe2O4 nanoparticles prepared by microwave combustion method. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.11.007] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Selvam NCS, Manikandan A, Kennedy LJ, Vijaya JJ. Comparative investigation of zirconium oxide (ZrO2) nano and microstructures for structural, optical and photocatalytic properties. J Colloid Interface Sci 2013; 389:91-8. [DOI: 10.1016/j.jcis.2012.09.014] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 09/05/2012] [Accepted: 09/07/2012] [Indexed: 11/16/2022]
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Manikandan A, Sarkar B, Holla R, Vivek TR, Sujatha N. Quality assurance of dynamic parameters in volumetric modulated arc therapy. Br J Radiol 2012; 85:1002-10. [PMID: 22745206 DOI: 10.1259/bjr/19152959] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The purpose of this study was to demonstrate quality assurance checks for accuracy of gantry speed and position, dose rate and multileaf collimator (MLC) speed and position for a volumetric modulated arc treatment (VMAT) modality (Synergy S; Elekta, Stockholm, Sweden), and to check that all the necessary variables and parameters were synchronous. METHODS Three tests (for gantry position-dose delivery synchronisation, gantry speed-dose delivery synchronisation and MLC leaf speed and positions) were performed. RESULTS The average error in gantry position was 0.5° and the average difference was 3 MU for a linear and a parabolic relationship between gantry position and delivered dose. In the third part of this test (sawtooth variation), the maximum difference was 9.3 MU, with a gantry position difference of 1.2°. In the sweeping field method test, a linear relationship was observed between recorded doses and distance from the central axis, as expected. In the open field method, errors were encountered at the beginning and at the end of the delivery arc, termed the "beginning" and "end" errors. For MLC position verification, the maximum error was -2.46 mm and the mean error was 0.0153 ±0.4668 mm, and 3.4% of leaves analysed showed errors of >±1 mm. CONCLUSION This experiment demonstrates that the variables and parameters of the Synergy S are synchronous and that the system is suitable for delivering VMAT using a dynamic MLC.
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Sarkar B, Nandy M, Manikandan A, Basu P, Sujatha N, Ray DK, Senthilkumar P, Ray S, Roy SS, Ray A, Basu S, Bhattacharya K. SU-E-T-57: Estimation of Uncertainty in Dose Delivery Due to MLC Position Inaccuracies by Inverse Derivative Method during Volumetric Modulated Arc Therapy Delivery by Elekta Beam Modulator. Med Phys 2012. [DOI: 10.1118/1.4735113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Manikandan A, Sarkar B, Nandy M, Sujatha N, Mallik S, Goswami J. SU-E-T-51: Evaluation of Velocity Dependent Positional Error of Dynamic Multi Leaf Collimator during VMAT Delivery Using a Well Defined Mathematical Function. Med Phys 2012. [DOI: 10.1118/1.4735107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Manikandan A, Biplab S, David PA, Holla R, Vivek TR, Sujatha N. Relative dosimetrical verification in high dose rate brachytherapy using two-dimensional detector array IMatriXX. J Med Phys 2011; 36:171-5. [PMID: 21897562 PMCID: PMC3159223 DOI: 10.4103/0971-6203.83491] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 03/18/2011] [Accepted: 04/04/2011] [Indexed: 11/04/2022] Open
Abstract
For high dose rate (HDR) brachytherapy, independent treatment verification is needed to ensure that the treatment is performed as per prescription. This study demonstrates dosimetric quality assurance of the HDR brachytherapy using a commercially available two-dimensional ion chamber array called IMatriXX, which has a detector separation of 0.7619 cm. The reference isodose length, step size, and source dwell positional accuracy were verified. A total of 24 dwell positions, which were verified for positional accuracy gave a total error (systematic and random) of –0.45 mm, with a standard deviation of 1.01 mm and maximum error of 1.8 mm. Using a step size of 5 mm, reference isodose length (the length of 100% isodose line) was verified for single and multiple catheters of same and different source loadings. An error ≤1 mm was measured in 57% of tests analyzed. Step size verification for 2, 3, 4, and 5 cm was performed and 70% of the step size errors were below 1 mm, with maximum of 1.2 mm. The step size ≤1 cm could not be verified by the IMatriXX as it could not resolve the peaks in dose profile.
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Sarkar B, Manikandan A, Roy S, Senthilkumar P, Roy A, Basu S, Bhattachrya K, Ghosh B. SU-E-T-68: Beam Matching of Linear Accelerators by Using Mathematical Functions. Med Phys 2011. [DOI: 10.1118/1.3612019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Sarkar B, Manikandan A, Holla R. SU-E-T-141: Leaf Position Verification during Dynamic Beam Delivery of Volumetric Modulated Arc Therapy Using Electronic Portal Imaging Device. Med Phys 2011. [DOI: 10.1118/1.3612092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Ravikumar M, Sathiyan S, Supe S, Vivek TR, Manikandan A, Varatharaj C. Dosimetric verification of brain and head and neck intensity-modulated radiation therapy treatment using EDR2 films and 2D ion chamber array matrix. J Cancer Res Ther 2010; 6:179-84. [DOI: 10.4103/0973-1482.65233] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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