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Datta D, Gordon MS. Accelerating Coupled-Cluster Calculations with GPUs: An Implementation of the Density-Fitted CCSD(T) Approach for Heterogeneous Computing Architectures Using OpenMP Directives. J Chem Theory Comput 2023; 19:7640-7657. [PMID: 37878756 DOI: 10.1021/acs.jctc.3c00876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
An algorithm is presented for the coupled-cluster singles, doubles, and perturbative triples correction [CCSD(T)] method based on the density fitting or the resolution-of-the-identity (RI) approximation for performing calculations on heterogeneous computing platforms composed of multicore CPUs and graphics processing units (GPUs). The directive-based approach to GPU offloading offered by the OpenMP application programming interface has been employed to adapt the most compute-intensive terms in the RI-CCSD amplitude equations with computational costs scaling as O ( N O 2 N V 4 ) , O ( N O 3 N V 3 ) , and O ( N O 4 N V 2 ) (where NO and NV denote the numbers of correlated occupied and virtual orbitals, respectively) and the perturbative triples correction to execute on GPU architectures. The pertinent tensor contractions are performed using an accelerated math library such as cuBLAS or hipBLAS. Optimal strategies are discussed for splitting large data arrays into tiles to fit them into the relatively small memory space of the GPUs, while also minimizing the low-bandwidth CPU-GPU data transfers. The performance of the hybrid CPU-GPU RI-CCSD(T) code is demonstrated on pre-exascale supercomputers composed of heterogeneous nodes equipped with NVIDIA Tesla V100 and A100 GPUs and on the world's first exascale supercomputer named "Frontier", the nodes of which consist of AMD MI250X GPUs. Speedups within the range 4-8× relative to the recently reported CPU-only algorithm are obtained for the GPU-offloaded terms in the RI-CCSD amplitude equations. Applications to polycyclic aromatic hydrocarbons containing 16-66 carbon atoms demonstrate that the acceleration of the hybrid CPU-GPU code for the perturbative triples correction relative to the CPU-only code increases with the molecule size, attaining a speedup of 5.7× for the largest circumovalene molecule (C66H20). The GPU-offloaded code enables the computation of the perturbative triples correction for the C60 molecule using the cc-pVDZ/aug-cc-pVTZ-RI basis sets in 7 min on Frontier when using 12,288 AMD GPUs with a parallel efficiency of 83.1%.
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Affiliation(s)
- Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, 2416 Pammel Drive, Ames, Iowa 50011-2416, United States
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, 2416 Pammel Drive, Ames, Iowa 50011-2416, United States
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Zahariev F, Xu P, Westheimer BM, Webb S, Galvez Vallejo J, Tiwari A, Sundriyal V, Sosonkina M, Shen J, Schoendorff G, Schlinsog M, Sattasathuchana T, Ruedenberg K, Roskop LB, Rendell AP, Poole D, Piecuch P, Pham BQ, Mironov V, Mato J, Leonard S, Leang SS, Ivanic J, Hayes J, Harville T, Gururangan K, Guidez E, Gerasimov IS, Friedl C, Ferreras KN, Elliott G, Datta D, Cruz DDA, Carrington L, Bertoni C, Barca GMJ, Alkan M, Gordon MS. The General Atomic and Molecular Electronic Structure System (GAMESS): Novel Methods on Novel Architectures. J Chem Theory Comput 2023; 19:7031-7055. [PMID: 37793073 DOI: 10.1021/acs.jctc.3c00379] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
The primary focus of GAMESS over the last 5 years has been the development of new high-performance codes that are able to take effective and efficient advantage of the most advanced computer architectures, both CPU and accelerators. These efforts include employing density fitting and fragmentation methods to reduce the high scaling of well-correlated (e.g., coupled-cluster) methods as well as developing novel codes that can take optimal advantage of graphical processing units and other modern accelerators. Because accurate wave functions can be very complex, an important new functionality in GAMESS is the quasi-atomic orbital analysis, an unbiased approach to the understanding of covalent bonds embedded in the wave function. Best practices for the maintenance and distribution of GAMESS are also discussed.
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Affiliation(s)
- Federico Zahariev
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Peng Xu
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Bryce M Westheimer
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Simon Webb
- VeraChem LLC, 12850 Middlebrook Road, Suite 205, Germantown, Maryland 20874-5244, United States
| | - Jorge Galvez Vallejo
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
- Research School of Computer Science, Australian National University, Canberra, ACT 2601, Australia
| | - Ananta Tiwari
- EP Analytics, Inc., 9909 Mira Mesa Boulevard, Suite 230, San Diego, California 92131, United States
| | - Vaibhav Sundriyal
- Department of Computational Modeling and Simulation Engineering, Old Dominion University, Norfolk, Virginia 23529, United States
| | - Masha Sosonkina
- Department of Computational Modeling and Simulation Engineering, Old Dominion University, Norfolk, Virginia 23529, United States
| | - Jun Shen
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - George Schoendorff
- Propellants Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, United States
| | - Megan Schlinsog
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Tosaporn Sattasathuchana
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Klaus Ruedenberg
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Luke B Roskop
- Hewlett-Packard Enterprise, 2131 Lindau Lane #1000, Bloomington, Minnesota 55425, United States
| | | | - David Poole
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Athens, Georgia 30332, United States
| | - Piotr Piecuch
- Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, United States
| | - Buu Q Pham
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Vladimir Mironov
- Department of Chemistry, Kyungpook National University, Daegu 41566, South Korea
| | - Joani Mato
- Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, United States
| | - Sam Leonard
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Sarom S Leang
- EP Analytics, Inc., 9909 Mira Mesa Boulevard, Suite 230, San Diego, California 92131, United States
| | - Joe Ivanic
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Jackson Hayes
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Taylor Harville
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Karthik Gururangan
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Emilie Guidez
- Department of Chemistry, University of Colorado Denver, Denver, Colorado 80217, United States
| | - Igor S Gerasimov
- Department of Chemistry, Kyungpook National University, Daegu 41566, South Korea
| | - Christian Friedl
- Institut für Theoretische Physik, Johannes Kepler Universität Linz, Altenberger Str. 69, 4040 Linz, Austria
| | - Katherine N Ferreras
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - George Elliott
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Daniel Del Angel Cruz
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Laura Carrington
- EP Analytics, Inc., 9909 Mira Mesa Boulevard, Suite 230, San Diego, California 92131, United States
| | - Colleen Bertoni
- Argonne Leadership Computing Facility, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Giuseppe M J Barca
- Research School of Computer Science, Australian National University, Canberra, ACT 2601, Australia
| | - Melisa Alkan
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
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Engineer R, Datta D, Gudi S, Krishnatry R, deSouza A, Ankathi SK, Kohle S, Saklani A. Dose Escalation Using Magnetic Resonance Guided High-Dose-Rate Endorectal Brachytherapy to Enhance Clinical Response after Neoadjuvant Radiotherapy in Rectal Adenocarcinoma. Int J Radiat Oncol Biol Phys 2023; 117:e295. [PMID: 37785083 DOI: 10.1016/j.ijrobp.2023.06.2304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) To assess the proportion of patients with rectal adenocarcinoma achieving clinical complete response after neoadjuvant chemoradiation (NACTRT) and MR guided endorectal brachytherapy boost (MR-ERBT) MATERIALS/METHODS: Patients with rectal cancers (T2-T4/N0-N+) treated with concurrent chemoradiotherapy (50Gy/25# with Capecitabine) between June-2017 to April-2022. Post RT, patients having residual non-circumferential lesions <8cm in length were administered escalated-dose MR-ERBT with Ir192 HDR source. A median dose of 12Gy (8-15Gy) in 3 (2-3) fractions at 3-5 day intervals was delivered using MR-ERBT after external radiation. Data on near complete/complete clinical response (nCR/cCR) rates, local regrowth rates and clinical outcome were collected for analysis. RESULTS Of the 145 patients who received MR-ERBT, majority were staged as T3(78.7%) and N1-2 (77.5%) rectal cancers. Median tumor length was 4cm and 123 (85%) of the tumors were located in the lower rectum (0-5cm from anal verge). Seventy-six (52%) patients achieved cCR or nCR (37 cCR, 39 nCR) and were advised observation or watch and wait (WW) management. The 69 patients having partial response were advised surgery. The patients having nCR 16 (29%) underwent resection, of these 10 (62%) had pathological complete response (pCR). The patients with partial or poor response, 57 underwent resection and of these 11 (19%) had pCR, 12 patients refused surgery due to fear of permanent stoma and continued to be on follow up. Of the 79 patients undergoing resection, 36 (45.5%) had sphincter preserving surgeries. At the median follow up of 30 months, local regrowth was seen in 8 (10.5%) of patients on WW and 6 were surgically salvaged while other 2 had synchronous metastatic relapse. Thus, 56 (41%) achieved organ preservation and continued to be on WW management. Twelve (8,2%) patients developed distant metastasis in the entire cohort, 3 in the WW group and 9 in the resected group. There were no pelvic recurrences seen in the resected patients. The disease-free survival at 3 years were (96.1% vs 89% Observation vs. resected (p_0.05) respectively. The overall survival at 3 years were (93% vs 98% Observation vs. resected (p_0.44) respectively. Late rectal toxicity was observed in 16(11%) patients on observation CONCLUSION: Dose Escalated MR-EBRT is an effective and safe method to enhance complete clinical response, thus improving the rate of organ preservation for distal rectal cancers.
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Affiliation(s)
- R Engineer
- Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
| | - D Datta
- Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
| | - S Gudi
- Tata Memorial Centre, Mumbai, India
| | - R Krishnatry
- Department of Radiation Oncology, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
| | - A deSouza
- Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
| | - S K Ankathi
- Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
| | - S Kohle
- Tata Memorial Centre, Mumbai, Maharashtra, India
| | - A Saklani
- Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India
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Pham BQ, Carrington L, Tiwari A, Leang SS, Alkan M, Bertoni C, Datta D, Sattasathuchana T, Xu P, Gordon MS. Porting fragmentation methods to GPUs using an OpenMP API: Offloading the resolution-of-the-identity second-order Møller-Plesset perturbation method. J Chem Phys 2023; 158:2887208. [PMID: 37114705 DOI: 10.1063/5.0143424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Using an OpenMP Application Programming Interface, the resolution-of-the-identity second-order Møller-Plesset perturbation (RI-MP2) method has been off-loaded onto graphical processing units (GPUs), both as a standalone method in the GAMESS electronic structure program and as an electron correlation energy component in the effective fragment molecular orbital (EFMO) framework. First, a new scheme has been proposed to maximize data digestion on GPUs that subsequently linearizes data transfer from central processing units (CPUs) to GPUs. Second, the GAMESS Fortran code has been interfaced with GPU numerical libraries (e.g., NVIDIA cuBLAS and cuSOLVER) for efficient matrix operations (e.g., matrix multiplication, matrix decomposition, and matrix inversion). The standalone GPU RI-MP2 code shows an increasing speedup of up to 7.5× using one NVIDIA V100 GPU with one IBM 42-core P9 CPU for calculations on fullerenes of increasing size from 40 to 260 carbon atoms using the 6-31G(d)/cc-pVDZ-RI basis sets. A single Summit node with six V100s can compute the RI-MP2 correlation energy of a cluster of 175 water molecules using the correlation consistent basis sets cc-pVDZ/cc-pVDZ-RI containing 4375 atomic orbitals and 14 700 auxiliary basis functions in ∼0.85 h. In the EFMO framework, the GPU RI-MP2 component shows near linear scaling for a large number of V100s when computing the energy of an 1800-atom mesoporous silica nanoparticle in a bath of 4000 water molecules. The parallel efficiencies of the GPU RI-MP2 component with 2304 and 4608 V100s are 98.0% and 96.1%, respectively.
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Affiliation(s)
- Buu Q Pham
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | - Melisa Alkan
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Colleen Bertoni
- Leadership Computing Facility, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | | | - Peng Xu
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
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Galvez Vallejo JL, Tow GM, Maginn EJ, Pham BQ, Datta D, Gordon MS. Quantum Chemical Modeling of Propellant Degradation. J Phys Chem A 2023; 127:1874-1882. [PMID: 36791340 DOI: 10.1021/acs.jpca.2c08722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
An ab initio quantum chemical approach for the modeling of propellant degradation is presented. Using state-of-the-art bonding analysis techniques and composite methods, a series of potential degradation reactions are devised for a sample hydroxyl-terminated-polybutadiene (HTPB) type solid fuel. By applying thermochemical procedures and isodesmic reactions, accurate thermochemical quantities are obtained using a modified G3 composite method based on the resolution of the identity. The calculated heats of formation for the different structures produced presents an ∼2 kcal/mol average error when compared against experimental values.
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Affiliation(s)
- Jorge L Galvez Vallejo
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Garrett M Tow
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Edward J Maginn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Buu Q Pham
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50014, United States
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Sarkar A, Dhar S, Bera S, Chakravarti M, Verma A, Prasad P, Saha A, Bhuniya A, Guha I, Roy S, Banerjee S, Baral R, Datta D, Bose A. 213P Type-1 diabetes restricts melanoma growth by reprogramming intra-tumoral T cell metabolism. Immuno-Oncology and Technology 2022. [DOI: 10.1016/j.iotech.2022.100324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Engineer R, Datta D, Saklani A, deSouza A, Baheti A, Ankathi S, Krishnatry R, Gudi S, Patil P. Reduction of Tumor Length by >50%, Post Neoadjuvant Chemoradiation as a Predictor for Complete Response and Organ Preservation in Rectal Cancer. Int J Radiat Oncol Biol Phys 2022. [DOI: 10.1016/j.ijrobp.2022.07.1021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Pascual Reguant L, Tian T, Datta D, Cianferoni D, Kourtis S, Gañez-Zapater A, Cannatá C, Serra-Camprubi Q, Espinar L, Guirola M, Querol J, Miró-Canturri A, Arribas J, Serrano L, Peiró S, Sdelci S. Interactions between BRD4 short, LOXL2, and MED1 drive cell cycle transcription in triple-negative breast cancer. Eur J Cancer 2022. [DOI: 10.1016/s0959-8049(22)00966-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Proud D, Datta D, Ketchell I, Douglas M, Manning DE, Addy C, Lau D, Duckers J. P160 “Seeing a trend” - increasing vitamin A levels on elexacaftor/tezacaftor/ivacaftor therapy. J Cyst Fibros 2022. [DOI: 10.1016/s1569-1993(22)00491-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Basu P, Sarangapani R, Datta D, Venkatraman B. Optimization Studies of Elemental Composition of Composite Polymer for Neutron Shielding Using Factorial Design Analysis. NUCL TECHNOL 2022. [DOI: 10.1080/00295450.2021.2018275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Pew Basu
- Indira Gandhi Centre for Atomic Research, Safety, Quality & Resource Management Group, Kalpakkam, Tamilnadu–603102, India
- Homi Bhabha National Institute, Kalpakkam, Tamilnadu–603102, India
| | - R. Sarangapani
- Indira Gandhi Centre for Atomic Research, Safety, Quality & Resource Management Group, Kalpakkam, Tamilnadu–603102, India
| | - D. Datta
- SRM Institute of Science & Technology, Department of Mathematics, Kattankulathur, Tamilnadu–603203, India
| | - B. Venkatraman
- Indira Gandhi Centre for Atomic Research, Safety, Quality & Resource Management Group, Kalpakkam, Tamilnadu–603102, India
- Homi Bhabha National Institute, Kalpakkam, Tamilnadu–603102, India
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Duckers J, Fitzgerald R, Proud D, Addy C, Datta D. Forewarned is forearmed: The cardiovascular time bomb in Cystic Fibrosis. J Cyst Fibros 2021; 21:551-552. [PMID: 34903495 DOI: 10.1016/j.jcf.2021.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 10/19/2022]
Affiliation(s)
- J Duckers
- Cardiff and Vale University Health Board, Wales, United Kingdom.
| | | | - D Proud
- Cardiff and Vale University Health Board, Wales, United Kingdom
| | - C Addy
- Cardiff and Vale University Health Board, Wales, United Kingdom
| | - D Datta
- Cardiff and Vale University Health Board, Wales, United Kingdom
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Pham BQ, Datta D, Gordon MS. PDG: A Composite Method Based on the Resolution of the Identity. J Phys Chem A 2021; 125:9421-9429. [PMID: 34658243 DOI: 10.1021/acs.jpca.1c06186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Gaussian-3 (G3) composite approach for thermochemical properties is revisited in light of the enhanced computational efficiency and reduced memory costs by applying the resolution-of-the-identity (RI) approximation for two-electron repulsion integrals (ERIs) to the computationally demanding component methods in the G3 model: the energy and gradient computations via the second-order Møller-Plesset perturbation theory (MP2) and the energy computations using the coupled-cluster singles-doubles method augmented with noniterative triples corrections [CCSD(T)]. Efficient implementation of the RI-based methods is achieved by employing a hybrid distributed/shared memory model based on MPI and OpenMP. The new variant of the G3 composite approach based on the RI approximation is termed the RI-G3 scheme, or alternatively the PDG method. The accuracy of the new RI-G3/PDG scheme is compared to the "standard" G3 composite approach that employs the memory-expensive four-center ERIs in the MP2 and CCSD(T) calculations. Taking the computation of the heats of formation of the closed-shell molecules in the G3/99 test set as a test case, it is demonstrated that the RI approximation introduces negligible changes to the mean absolute errors relative to the standard G3 model (less than 0.1 kcal/mol), while the standard deviations remain unaltered. The efficiency and memory requirements for the RI-MP2 and RI-CCSD(T) methods are compared to the standard MP2 and CCSD(T) approaches, respectively. The hybrid MPI/OpenMP-based RI-MP2 energy plus gradient computation is found to attain a 7.5× speedup over the standard MP2 calculations. For the most demanding CCSD(T) calculations, the application of the RI approximation is found to nearly halve the memory demand, confer about a 4-5× speedup for the CCSD iterations, and reduce the computational time for the compute-intensive triples correction step by several hours.
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Datta D, Gordon MS. A Massively Parallel Implementation of the CCSD(T) Method Using the Resolution-of-the-Identity Approximation and a Hybrid Distributed/Shared Memory Parallelization Model. J Chem Theory Comput 2021; 17:4799-4822. [PMID: 34279094 DOI: 10.1021/acs.jctc.1c00389] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A parallel algorithm is described for the coupled-cluster singles and doubles method augmented with a perturbative correction for triple excitations [CCSD(T)] using the resolution-of-the-identity (RI) approximation for two-electron repulsion integrals (ERIs). The algorithm bypasses the storage of four-center ERIs by adopting an integral-direct strategy. The CCSD amplitude equations are given in a compact quasi-linear form by factorizing them in terms of amplitude-dressed three-center intermediates. A hybrid MPI/OpenMP parallelization scheme is employed, which uses the OpenMP-based shared memory model for intranode parallelization and the MPI-based distributed memory model for internode parallelization. Parallel efficiency has been optimized for all terms in the CCSD amplitude equations. Two different algorithms have been implemented for the rate-limiting terms in the CCSD amplitude equations that entail O(NO2NV4) and O(NO3NV3)-scaling computational costs, where NO and NV denote the number of correlated occupied and virtual orbitals, respectively. One of the algorithms assembles the four-center ERIs requiring NV4 and NO2NV2-scaling memory costs in a distributed manner on a number of MPI ranks, while the other algorithm completely bypasses the assembling of quartic memory-scaling ERIs and thus largely reduces the memory demand. It is demonstrated that the former memory-expensive algorithm is faster on a few hundred cores, while the latter memory-economic algorithm shows a better strong scaling in the limit of a few thousand cores. The program is shown to exhibit a near-linear scaling, in particular for the compute-intensive triples correction step, on up to 8000 cores. The performance of the program is demonstrated via calculations involving molecules with 24-51 atoms and up to 1624 atomic basis functions. As the first application, the complete basis set (CBS) limit for the interaction energy of the π-stacked uracil dimer from the S66 data set has been investigated. This work reports the first calculation of the interaction energy at the CCSD(T)/aug-cc-pVQZ level without local orbital approximation. The CBS limit for the CCSD correlation contribution to the interaction energy was found to be -8.01 kcal/mol, which agrees very well with the value -7.99 kcal/mol reported by Schmitz, Hättig, and Tew [ Phys. Chem. Chem. Phys. 2014, 16, 22167-22178]. The CBS limit for the total interaction energy was estimated to be -9.64 kcal/mol.
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Affiliation(s)
- Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, 2416 Pammel Drive, Ames 50011-2416, Iowa United States of America
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, 2416 Pammel Drive, Ames 50011-2416, Iowa United States of America
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Chaudhary RK, Kumar R, Sharma SD, Datta D. Computation of epistemic uncertainty due to limited data samples in small field dosimetry using Fuzzy Set Theory. Br J Radiol 2021; 94:20190561. [PMID: 33684311 DOI: 10.1259/bjr.20190561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To estimate the epistemic (or fuzzy) uncertainty, arising due to limited data samples in the measurement of the output factors (OFs) of the small fields using Fuzzy Set Theory (FST). METHODS EBT3 film samples of size 50 × 50 mm2 were used for the measurement of the OF of stereotactic radiosurgery (SRS) cones of size 4, 6, 7.5, 10, 12.5 and 15 mm diameter, normalized with respect to the output of 100 × 100 mm2 open field size. Three measurements were done per cone/field size. Red color channel was chosen for the dosimetry purpose, net optical density (NOD) was converted to the dose using non-linear relation. To estimate the epistemic uncertainty associated with the measured OFs due to limited number of data samples, a triangular fuzzy number (TFN) was assumed as the fuzziness in the dose delivered by the individual SRS cone/field. Uncertainty in the OF was estimated by applying the Fuzzy Vertex Method (FVM). The membership functions of the OF were constructed for each cone size and the nature of the uncertainty in the OF of the cones was expressed in the terms of its fuzziness. For the sake of completeness of the study, the statistical uncertainty involved in the procedure has also been calculated. RESULTS The statistical and fuzzy uncertainties in the measurement of OF of cones range from 3.28 to 6.25% and 2.58 to 5.44% respectively. The smallest cone of 4 mm has the largest values of statistical and fuzzy uncertainties. The membership functions of the OF for the studied cones were triangular in nature. CONCLUSION The epistemic uncertainty arising due to limited number of data samples holds a significant fraction of the prescribed dose, and therefore, should not be ignored in the total uncertainty estimation. ADVANCES IN KNOWLEDGE This study highlights the significance of epistemic component of measurement uncertainty arising out due to the insufficient/limited number of measurements of a quantity.
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Affiliation(s)
- Rahul Kumar Chaudhary
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Rajesh Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India
| | - S D Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
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Datta D, Saitow M, Sandhöfer B, Neese F. 57Fe Mössbauer parameters from domain based local pair-natural orbital coupled-cluster theory. J Chem Phys 2020; 153:204101. [PMID: 33261496 DOI: 10.1063/5.0022215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report on applications of the domain based local pair-natural orbital (PNO) coupled-cluster method within the singles and doubles approximation (DLPNO-CCSD) to the calculation of 57Fe isomer shifts and quadrupole splittings in a small training set of iron complexes consisting of large molecular ligands and iron atoms in varying charge, spin, and oxidation states. The electron densities and electric field gradients needed for these calculations were obtained within the recently implemented analytic derivative scheme. A method for the direct treatment of scalar relativistic effects in the calculation of effective electron densities is described by using the first-order Douglas-Kroll-Hess Hamiltonian and a Gaussian charge distribution model for the nucleus. The performance of DLPNO-CCSD is compared with four modern-day density functionals, namely, RPBE, TPSS, B3LYP, and B2PLYP, as well as with the second-order Møller-Plesset perturbation theory. An excellent correlation between the calculated electron densities and the experimental isomer shifts is attained with the DLPNO-CCSD method. The correlation constant a obtained from the slope of the linear correlation plot is found to be ≈-0.31 a.u.3 mm s-1, which agrees very well with the experimental calibration constant α = -0.31 ± 0.04 a.u.3 mm s-1. This value of a is obtained consistently using both nonrelativistic and scalar relativistic DLPNO-CCSD electron densities. While the B3LYP and B2PLYP functionals achieve equally good correlation between theory and experiment, the correlation constant a is found to deviate from the experimental value. Similar trends are observed also for quadrupole splittings. The value of the nuclear quadrupole moment for 57Fe is estimated to be 0.15 b at the DLPNO-CCSD level. This is consistent with previous results and is here supported by a higher level of theory. The DLPNO-CCSD results are found to be insensitive to the intrinsic approximations in the method, in particular the PNO occupation number truncation error, while the results obtained with density functional theory (DFT) are found to depend on the choice of the functional. In a statistical sense, i.e., on the basis of the linear regression analysis, however, the accuracies of the DFT and DLPNO-CCSD results can be considered comparable.
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Affiliation(s)
- Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, 201 Spedding Hall, 2416 Pammel Drive, Ames, Iowa 50011-2416, USA
| | - Masaaki Saitow
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | | | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
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16
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Ziaj S, Tseliou F, Datta D, Abbott RA. Skin cancer awareness and prevention behaviour in Wales. Br J Dermatol 2020; 184:764-765. [PMID: 33179262 DOI: 10.1111/bjd.19676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 11/28/2022]
Affiliation(s)
- S Ziaj
- Department of Dermatology, University Hospital Wales, Cardiff, UK
| | - F Tseliou
- HealthWise Wales, Division of Population Medicine, Cardiff University, UK
| | - D Datta
- Department of Biochemistry, Cardiff and Vale University Health Board, Cardiff, UK
| | - R A Abbott
- Department of Dermatology, University Hospital Wales, Cardiff, UK
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17
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Agarwal TK, Sahoo BK, Shetty T, Gaware JJ, Kumara S, Karunakara N, Sapra BK, Datta D. Numerical simulation of 222Rn profiling in an experimental chamber using CFD technique. J Environ Radioact 2020; 220-221:106298. [PMID: 32560887 DOI: 10.1016/j.jenvrad.2020.106298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 03/03/2020] [Accepted: 05/03/2020] [Indexed: 06/11/2023]
Abstract
Measurement of indoor 222Rn concentration and interpretation of distribution patterns are important for inhalation dosimetry in occupational and residential areas. Experimental determination of 222Rn concentration distribution and estimation of inhalation doses depend on the underlying aspects such as calibration of the detectors, accuracy of the techniques etc. Therefore, 222Rn concentration distribution needs to be very well understood in a closed domain for the controlled studies. In the recent times, Computational fluid dynamics (CFD) technique has gained a lot of attention for the prediction and visualization of indoor 222Rn concentration profiles and their mixing ability in the domain. The present study aims to simulate the effect of forced mixing on the 222Rn concentration profile in a 22 m3 experimental chamber. This chamber is designed for carrying out the controlled experiments, calibration and inter-comparison studies of various types of 222Rn detectors. Effect of different parameters such as time, flow rates, fan-off and fan-on conditions have been studied on the transient response, extent of the air mixing patterns and subsequently on 222Rn concentration profile in the chamber. Further, Non uniformity index (NUI) is introduced as a measure of the uniformity of the distribution in the closed domain. NUI is estimated for different cases in order to efficiently interpret the effect of above mentioned parameters on 222Rn profile in the chamber. This study will be useful to represent the turbulent conditions in real indoor domains and occupational facilities as U-mines during calibration and inter-comparison exercises of different 222Rn detectors.
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Affiliation(s)
- Tarun K Agarwal
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
| | - B K Sahoo
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Trilochana Shetty
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, Karnataka, 574199, India
| | - J J Gaware
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Sudeep Kumara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, Karnataka, 574199, India
| | - N Karunakara
- Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University, Mangalagangothri, Karnataka, 574199, India
| | - B K Sapra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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18
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Pradhan SM, Datta D, Pathan MS, Srivastava K, Selvam TP. ESTIMATION OF UNCERTAINTY IN MEASUREMENT OF DOSE EQUIVALENT AT LABORATORY LEVEL USING CASO4 :Dy-BASED TLD BADGE SYSTEM IN INDIA. Radiat Prot Dosimetry 2020; 188:135-147. [PMID: 31832666 DOI: 10.1093/rpd/ncz268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 07/20/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
The objective of this paper is to estimate the combined uncertainty in the measurement of dose equivalent at laboratory level using CaSO4:Dy-based thermoluminescent dosemeter badge system by including variations in the components of the system. The variability of performance of the system is analysed using random effects one way analysis of variance model. The model enables estimation of the overall variance of the performance of the sampled population. The population in the study comprises all possible indicated dose equivalents on irradiation of dosemeters to a specific dose equivalent and radiation quality. Coefficient of variation and combined uncertainty at 95% level of confidence in the measurement of Hp(10) due to S-Cs radiation quality are found to be 6.6 and 14.3%, respectively, at the dose level of 5.31 mSv. The above parameters in the measurement of in-use quantity, i.e. whole body dose or photon dose equivalent are found to be 7.4 and 16.4%, respectively. The performance of the monitoring system on relative response has been observed to be satisfactory. Various factors affecting the variability of performance of the system are identified for further improvement in coefficient of variation.
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Affiliation(s)
- S M Pradhan
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Munir S Pathan
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - Kshama Srivastava
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
| | - T Palani Selvam
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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19
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Barca GMJ, Bertoni C, Carrington L, Datta D, De Silva N, Deustua JE, Fedorov DG, Gour JR, Gunina AO, Guidez E, Harville T, Irle S, Ivanic J, Kowalski K, Leang SS, Li H, Li W, Lutz JJ, Magoulas I, Mato J, Mironov V, Nakata H, Pham BQ, Piecuch P, Poole D, Pruitt SR, Rendell AP, Roskop LB, Ruedenberg K, Sattasathuchana T, Schmidt MW, Shen J, Slipchenko L, Sosonkina M, Sundriyal V, Tiwari A, Galvez Vallejo JL, Westheimer B, Włoch M, Xu P, Zahariev F, Gordon MS. Recent developments in the general atomic and molecular electronic structure system. J Chem Phys 2020; 152:154102. [PMID: 32321259 DOI: 10.1063/5.0005188] [Citation(s) in RCA: 482] [Impact Index Per Article: 120.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A discussion of many of the recently implemented features of GAMESS (General Atomic and Molecular Electronic Structure System) and LibCChem (the C++ CPU/GPU library associated with GAMESS) is presented. These features include fragmentation methods such as the fragment molecular orbital, effective fragment potential and effective fragment molecular orbital methods, hybrid MPI/OpenMP approaches to Hartree-Fock, and resolution of the identity second order perturbation theory. Many new coupled cluster theory methods have been implemented in GAMESS, as have multiple levels of density functional/tight binding theory. The role of accelerators, especially graphical processing units, is discussed in the context of the new features of LibCChem, as it is the associated problem of power consumption as the power of computers increases dramatically. The process by which a complex program suite such as GAMESS is maintained and developed is considered. Future developments are briefly summarized.
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Affiliation(s)
- Giuseppe M J Barca
- Research School of Computer Science, Australian National University, Canberra, ACT 2601, Australia
| | - Colleen Bertoni
- Argonne Leadership Computing Facility, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Laura Carrington
- EP Analytics, 12121 Scripps Summit Dr. Ste. 130, San Diego, California 92131, USA
| | - Dipayan Datta
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Nuwan De Silva
- Department of Physical and Biological Sciences, Western New England University, Springfield, Massachusetts 01119, USA
| | - J Emiliano Deustua
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Dmitri G Fedorov
- Research Center for Computational Design of Advanced Functional Materials (CD-FMat), National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan
| | - Jeffrey R Gour
- Microsoft, 15590 NE 31st St., Redmond, Washington 98052, USA
| | - Anastasia O Gunina
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Emilie Guidez
- Department of Chemistry, University of Colorado Denver, Denver, Colorado 80217, USA
| | - Taylor Harville
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Stephan Irle
- Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Joe Ivanic
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Karol Kowalski
- Physical Sciences Division, Battelle, Pacific Northwest National Laboratory, K8-91, P.O. Box 999, Richland, Washington 99352, USA
| | - Sarom S Leang
- EP Analytics, 12121 Scripps Summit Dr. Ste. 130, San Diego, California 92131, USA
| | - Hui Li
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, USA
| | - Wei Li
- School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, Nanjing University, Nanjing 210023, People's Republic of China
| | - Jesse J Lutz
- Center for Computing Research, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Ilias Magoulas
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Joani Mato
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Vladimir Mironov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russian Federation
| | - Hiroya Nakata
- Kyocera Corporation, Research Institute for Advanced Materials and Devices, 3-5-3 Hikaridai Seika-cho, Souraku-gun, Kyoto 619-0237, Japan
| | - Buu Q Pham
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Piotr Piecuch
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - David Poole
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Spencer R Pruitt
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Alistair P Rendell
- Research School of Computer Science, Australian National University, Canberra, ACT 2601, Australia
| | - Luke B Roskop
- Cray Inc., a Hewlett Packard Enterprise Company, 2131 Lindau Ln #1000, Bloomington, Minnesota 55425, USA
| | - Klaus Ruedenberg
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | | | - Michael W Schmidt
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Jun Shen
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Lyudmila Slipchenko
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA
| | - Masha Sosonkina
- Department of Computational Modeling and Simulation Engineering, Old Dominion University, Norfolk, Virginia 23529, USA
| | - Vaibhav Sundriyal
- Department of Computational Modeling and Simulation Engineering, Old Dominion University, Norfolk, Virginia 23529, USA
| | - Ananta Tiwari
- EP Analytics, 12121 Scripps Summit Dr. Ste. 130, San Diego, California 92131, USA
| | - Jorge L Galvez Vallejo
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Bryce Westheimer
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Marta Włoch
- 530 Charlesina Dr., Rochester, Michigan 48306, USA
| | - Peng Xu
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Federico Zahariev
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA
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20
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Rout RP, Sahoo BK, Pal R, Dhabekar BS, Bakshi AK, Datta D. Investigation of 220Rn emanation and exhalation from soil samples of Larsemann Hills region, Antarctica. J Environ Radioact 2020; 214-215:106175. [PMID: 32063292 DOI: 10.1016/j.jenvrad.2020.106175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/08/2020] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
In the present study, thoron exhalation flux density were measured in the soil samples collected around the Indian station namely Bharati (69° 24.41' S, 76° 11.72' E) and its nearby islands in the Larsemann hills region of Antarctica. Further, dependency of thoron mass emanation rate and emanation coefficient on the soil grain size was studied by segregating the soil samples into four different grain size groups: 50-100 μm, 100-200 μm, 200-500 μm and 500-1000 μm which showed that both of them follow a decreasing trend with increase in grain size. A comparison of measured mass emanation rate between different soil samples showed that it had a larger variation for the smaller grain size which eventually decreased as grain size increased while emanation coefficient was observed to be nearly constant for all the grain size groups. The variation in emanation coefficient with respect to mean grain size has been investigated and an empirical exponential model has been proposed for predicting emanation coefficient for different grain sizes.
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Affiliation(s)
- R P Rout
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Mumbai, 400 094, India
| | - B K Sahoo
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
| | - R Pal
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Mumbai, 400 094, India
| | - B S Dhabekar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - A K Bakshi
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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21
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Chattaraj A, Selvam TP, Datta D. MONTE CARLO-BASED INVESTIGATION OF MICRODOSIMETRIC DISTRIBUTION OF HIGH ENERGY BRACHYTHERAPY SOURCES. Radiat Prot Dosimetry 2019; 187:115-128. [PMID: 31165891 DOI: 10.1093/rpd/ncz148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/26/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
FLUKA-based Monte Carlo calculations were carried out to study microdosimetric distributions in air and in water for encapsulated high energy brachytherapy sources (60Co, 137Cs, 192Ir and 169Yb) by simulating a Tissue Equivalent Proportional Counter (Model LET1/2) having sensitive diameter of 1. 27 cm for a site size of 1 μm. The study also included microdosimetric distributions of bare sources. When the sources are in air, for a given source, the source geometry does not affect the y¯F and y¯D values significantly. When the encapsulated 192Ir, 137Cs and 60Co sources are in water, y¯F and y¯D values increase with distance in water which is due to degradation in the energy of photons. Using the calculated values of y¯D, relative biological effectiveness (RBE) was obtained for the investigated sources. When 60Co, 137Cs and 192Ir sources are in water, RBE increases from 1.03 ± 0.01 to 1.17 ± 0.01, 1.24 ± 0.01 to 1.46 ± 0.02 and 1.50 ± 0.01 to 1.75 ± 0.03, respectively, when the distance was increased from 3-15 cm, whereas for 169Yb, RBE is about 2, independent of distance in water.
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Affiliation(s)
- Arghya Chattaraj
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai
- Homi Bhabha National Institute, Anushaktinagar, Mumbai
| | - T Palani Selvam
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai
- Homi Bhabha National Institute, Anushaktinagar, Mumbai
| | - D Datta
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Trombay, Mumbai
- Homi Bhabha National Institute, Anushaktinagar, Mumbai
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22
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Pathan MS, Pradhan SM, Datta D, Selvam TP. STUDY OF EFFECT OF CONSECUTIVE HEATING ON THERMOLUMINESCENCE GLOW CURVES OF MULTI-ELEMENT TL DOSEMETER IN HOT GAS-BASED READER SYSTEM. Radiat Prot Dosimetry 2019; 187:509-517. [PMID: 31650175 DOI: 10.1093/rpd/ncz191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/17/2019] [Accepted: 08/06/2019] [Indexed: 06/10/2023]
Abstract
The objective of this paper is to study the effect of consecutive heating of TL elements of a thermoluminescence dosemeter (TLD) card in hot N2 gas-based TLD badge reader. The effect is studied by theoretical simulations of clamped heating profiles of the discs and resulting TL glow curves. The simulated temperature profile accounts for heat transfer to disc from hot gas as well as radiative and convective heat exchanges between the disc and the surrounding. The glow curves are simulated using 10 component glow peak model for CaSO4:Dy using the simulated temperature profile. The shape of the simulated glow curves and trend in total TL signal of the three discs were observed to match closely with the experimental observations when elevated surrounding temperature was considered for simulation. It is concluded that the readout (heating) of adjacent TLD disc affects the surrounding temperature leading to the changes in temperature profile of the next disc.
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Affiliation(s)
- Munir S Pathan
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - S M Pradhan
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400 094, India
| | - T Palani Selvam
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai, 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400 094, India
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23
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Vandana S, Bakshi AK, Behrens R, Chattaraj A, Saxena SK, Dhami PS, Panja S, Jagasia P, Selvam TP, Dash A, Datta D. MEASUREMENT OF OPERATIONAL QUANTITIES Hp(0.07) AND Hp(3) FOR INDIGENOUSLY DEVELOPED 106Ru/106Rh SOURCE USING AN EXTRAPOLATION CHAMBER. Radiat Prot Dosimetry 2019; 185:376-386. [PMID: 30916771 DOI: 10.1093/rpd/ncz024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/02/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
In the present study, a prototype 106Ru/106Rh source was fabricated using high level liquid waste from reactor fuel, fixed in a stainless steel housing with a window and backing made of silver. The study involves measurement of the operational quantities Hp(0.07), Hp(3) and the percentage depth dose (PDD) using an extrapolation chamber. It also involves determination of necessary correction factors to arrive at Hp(0.07) and Hp(3) following International Organisation for Standardisation (ISO) and methods suggested in literature. The study facilitates incorporation of the 106Ru/106Rh source as a beta reference source for quality assurance programme in TLD personnel monitoring as per the guidelines of ISO.
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Affiliation(s)
- S Vandana
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - A K Bakshi
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai , India
| | - R Behrens
- Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, Braunschweig, Germany
| | - A Chattaraj
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - S K Saxena
- Radiopharmaceutical Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - P S Dhami
- Fuel Reprocessing Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - S Panja
- Fuel Reprocessing Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - P Jagasia
- Fuel Reprocessing Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - T Palani Selvam
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai , India
| | - A Dash
- Radiopharmaceutical Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
| | - D Datta
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai , India
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Chattaraj A, Selvam TP, Datta D. INVESTIGATION OF APPLICABILITY OF PURE PROPANE GAS FOR MICRODOSIMETRY AT NEUTRON FIELDS: A MONTE CARLO STUDY. Radiat Prot Dosimetry 2019; 185:74-86. [PMID: 30576567 DOI: 10.1093/rpd/ncy261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/01/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
Applicability of pure propane gas for microdosimetric measurements in neutron fields was investigated using the FLUKA Monte Carlo code. Monoenergetic neutrons in the energy range 1 keV-20 MeV and the ISO-neutron sources such as 241Am-Be, 241Am-B, 252Cf and 252Cf + D2O were considered in the present study. The tissue-equivalent proportional counter (TEPC) simulated in the study was LET-1/2 (by Far West Technology) with site sizes 1, 2 and 8 μm. The study demonstrates that for a given site size, the TEPC filled with tissue-equivalent propane and pure propane gases produce similar microdosimetric distributions when the density of pure propane gas is lowered appropriately. For the ISO-neutron sources, the density of propane gas requires scaling by a factor 0.85. For the monoenergetic neutrons, depending upon the neutron energy, the values of scaling factors are in the range of 0.58-0.93.
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Affiliation(s)
- Arghya Chattaraj
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - T Palani Selvam
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - D Datta
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
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Kakade NR, Kumar R, Sharma SD, Datta D. Equivalence of silver and gold nanoparticles for dose enhancement in nanoparticle-aided brachytherapy. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab3d0c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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26
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Bakshi A, Pal R, Dawn S, Dhabekar B, Datta D. Measurement of environmental radiation and analysis of microdosimetric spectra of cosmic rays during the 35th expedition to Indian station Bharati, Antarctica. RADIAT MEAS 2019. [DOI: 10.1016/j.radmeas.2019.106122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Roy T, Sharma A, Datta D, Balasubramaniam R. Molecular dynamics simulation of single discharge and dimensionless correlation with actual material removal in micro electrical discharge machining. Molecular Simulation 2019. [DOI: 10.1080/08927022.2019.1626988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- T. Roy
- Homi Bhabha National Institute, Mumbai, India
| | - A. Sharma
- Homi Bhabha National Institute, Mumbai, India
| | - D. Datta
- Homi Bhabha National Institute, Mumbai, India
- Bhabha Atomic Research Centre, Mumbai, India
| | - R. Balasubramaniam
- Homi Bhabha National Institute, Mumbai, India
- Bhabha Atomic Research Centre, Mumbai, India
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28
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Sharma R, Sharma SD, Sarkar PS, Singh B, Agrawal AK, Datta D. Phantom-Based Feasibility Studies on Phase-Contrast Mammography at Indian Synchrotron Facility Indus-2. J Med Phys 2019; 44:39-48. [PMID: 30983770 PMCID: PMC6438051 DOI: 10.4103/jmp.jmp_98_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Introduction: Use of synchrotron radiation (SR) X-ray source in medical imaging has shown great potential for improving soft-tissue image contrast such as the breast. The present study demonstrates quantitative X-ray phase-contrast imaging (XPCI) technique derived from propagation-dependent phase change observed in the breast tissue-equivalent test materials. Materials and Methods: Indian synchrotron facility (Indus-2, Raja Ramanna Centre of Advanced Technology [RRCAT]) was used to carry out phantom feasibility study on phase-contrast mammography. Different phantoms and samples, including locally fabricated breast tissue-equivalent phantoms were used to perform absorption and phase mode imaging using 12 and 16 keV SR X-ray beam. Edge-enhancement index (EEI) and edge enhancement to noise ratio (EE/N) were measured for all the images. Absorbed dose to air values were calculated for 12 and 16 keV SR X-ray beam using the measured SR X-ray photon flux at the object plane and by applying the standard radiation dosimetry formalism. Results and Conclusion: It was observed in case of all the phantoms and test samples that EEI and EE/N values are relatively higher for images taken in the phase mode. The absorbed dose to air at imaging plane was found to be 75.59 mGy and 28.9 mGy for 12 and 16 keV SR energies, respectively. However, these dose values can be optimized by reducing the image acquisition time without compromising the image quality when clinical samples are imaged. This work demonstrates the feasibility of XPCI in mammography using 12 and 16 keV SR X-ray beams.
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Affiliation(s)
- Reena Sharma
- Division of Radiological Physics and Advisory, Bhabha Atomic Research Centre, CT and CRS, Mumbai, Maharashtra, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - S D Sharma
- Division of Radiological Physics and Advisory, Bhabha Atomic Research Centre, CT and CRS, Mumbai, Maharashtra, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - P S Sarkar
- Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India.,Division of Technical Physics, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra, India
| | - B Singh
- Division of Technical Physics, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra, India
| | - A K Agrawal
- Division of Technical Physics, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra, India
| | - D Datta
- Division of Radiological Physics and Advisory, Bhabha Atomic Research Centre, CT and CRS, Mumbai, Maharashtra, India.,Department of Atomic Energy, Homi Bhabha National Institute, Mumbai, Maharashtra, India
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29
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Datta D, Gauss J. Accurate Prediction of Hyperfine Coupling Tensors for Main Group Elements Using a Unitary Group Based Rigorously Spin-Adapted Coupled-Cluster Theory. J Chem Theory Comput 2019; 15:1572-1592. [PMID: 30698956 DOI: 10.1021/acs.jctc.8b01048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the development of a perturbative triples correction scheme for the previously reported unitary group based spin-adapted combinatoric open-shell coupled-cluster (CC) singles and doubles (COS-CCSD) approach and report on the applications of the newly developed method, termed "COS-CCSD(T)", to the calculation of hyperfine coupling (HFC) tensors for radicals consisting of hydrogen, second- and third-row elements. The COS-CCSD(T) method involves a single noniterative step with [Formula: see text] scaling of the computational cost for the calculation of triples corrections to the energy. The key feature of this development is the use of spatial semicanonical orbitals generated from standard restricted open-shell Hartree-Fock (ROHF) orbitals, which allows the unperturbed Hamiltonian operator to be defined in terms of a diagonal spin-free Fock operator. The HFC tensors are computed as a first-order property via implementation of an analytic derivative scheme. The required one-particle spin density matrix is computed by using one- and two-particle spin-free density matrices that are obtained from the analytic derivative implementation, in this way avoiding the use of any spin-dependent operator and maintaining spin adaptation of the CC wavefunction. Benchmark calculations of HFC tensors for a set of 21 radicals indicate reasonably good agreement of the COS-CCSD(T) results with experiment and a consistent improvement over the COS-CCSD method. We demonstrate that the accuracies of the isotropic hyperfine coupling constants obtained in unrestricted HF (UHF) reference based spin-orbital CCSD(T) calculations deteriorate when spin contamination in the UHF wavefunction is large, and the results may even become qualitatively incorrect when spin polarization is the driving mechanism. Within a similar noniterative perturbative treatment of triple excitations, the spin-adapted COS-CCSD(T) approach produces accurate results, thus ensuring cost-effectiveness together with reliability.
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Affiliation(s)
- Dipayan Datta
- Institut für Physikalische Chemie , Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14 , 55128 Mainz , Germany
| | - Jürgen Gauss
- Institut für Physikalische Chemie , Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14 , 55128 Mainz , Germany
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30
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Sahoo S, Shrivastava V, Selvam TP, Bakshi AK, Kumar R, Rama P, Datta D, Chinnaesakki S, Saxena SK, Kumar Y, Dash A. Dosimetry of indigenously developed 177Lu patch source for surface brachytherapy-Experimental and Monte Carlo methods. J Radiol Prot 2019; 39:54-70. [PMID: 30523912 DOI: 10.1088/1361-6498/aaeeb6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This paper describes the evaluation of dosimetry characteristics of an in-house developed 177Lu skin patch source for treatment of non-melanoma skin cancer. A 177Lu skin patch source based on Nafion-115 membrane backbone containing 3.46 ± 0.01 mCi of activity was used. Activity measurement of the patch source was based on gamma ray spectrometry using a HPGe detector. The efficiencies of the HPGe detector were fitted using an orthogonal polynomial function. The absorbed dose rate to water at 5 μm depth in water was determined using an extrapolation chamber, EBT3 Gafchromic film and compared with Monte Carlo methods. The correction factors such as Bragg-Gray stopping power ratio of water-to-air and chamber wall material being different from water, needed to be applied on measurements for establishing the dose rate at 5 μm depth, were calculated using the Monte Carlo method. Absorbed dose rate at 5 μm depth in water (surface dose rate) measured using an extrapolation chamber and EBT3 Gafchromic film were 9.9 ± 0.7 and 8.2 ± 0.1 Gy h-1 mCi-1 respectively for the source activity of 3.46 ± 0.01 mCi. The surface dose rate calculated using the Monte Carlo method was 8.7 ± 0.2 Gy h-1 mCi-1, which agrees reasonably well with measurement. The measured dose rate per mCi offers scope for ascertaining treatment time required to deliver the dose for propitious therapeutic outcome. Additionally, on-axis depth dose and lateral dose profiles at 5 μm and 1 mm depth in water phantom were also calculated using the Monte Carlo method.
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Affiliation(s)
- Sridhar Sahoo
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai-400 085, India. Homi Bhabha National Institute, Mumbai-400 094, India
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31
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Abstract
Purpose: The purpose of the present study was to evaluate the practicability of liquid ionization chamber (LIC) for pretreatment dose verification of the advanced radiotherapy techniques such as volumetric modulated arc therapy (VMAT). Materials and Methods: The dosimetric characteristics of LIC such as repeatability, sensitivity, monitor unit linearity, dose rate dependence, angular dependence, voltage-current response, and output factors were investigated in 6 MV therapeutic X-ray beams. The LIC was cross-calibrated against 0.125-cc air-filled thimble ionization chamber. A dedicated dosimetry insert made up of Perspex to incorporate the LIC at proper location in the intensity-modulated radiation therapy thorax phantom was locally fabricated. The collection efficiency and ion recombination correction factor was determined using the two-dose rate method. Pretreatment dose verification measurement of VMAT treatment plans were carried out using the liquid ionization chamber as well as small volume (0.125 cc) air-filled thimble ionization chamber. The measured dose values by the two dosimeters and TPS calculated dose at a given point were compared. Results: The relative percentage differences between the TPS calculated and measured doses were within ± 1.57% for LIC and ± 2.21% for 0.125 cc ionization chamber, respectively. Conclusions: The measured dose values by the two dosimeters and TPS calculated dose at a given point were found comparable suggesting that the LIC could be a good choice of dosimeter for pretreatment dose verification in VMAT.
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Affiliation(s)
- Nitin R Kakade
- Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Anushaktinagar, Mumbai, Maharashtra, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, Maharashtra, India
| | - Rajesh Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Anushaktinagar, Mumbai, Maharashtra, India
| | - Sunil Dutt Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Anushaktinagar, Mumbai, Maharashtra, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, Maharashtra, India
| | - Vikram Mittal
- Department of Radiotherapy, P. D. Hinduja National Hospital, Mumbai, Maharashtra, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Anushaktinagar, Mumbai, Maharashtra, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai, Maharashtra, India
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32
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Chandrasekhar S, Pradhan SM, Bhattacharya M, Bakshi AK, Datta D. A new look at blind test procedures in personnel monitoring. Radiat Prot Environ 2019. [DOI: 10.4103/rpe.rpe_7_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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33
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Sharma R, Sharma SD, Sarkar PS, Datta D. Imaging and Dosimetric Study on Direct Flat-Panel Detector-Based Digital Mammography System. J Med Phys 2018; 43:255-263. [PMID: 30636851 PMCID: PMC6299749 DOI: 10.4103/jmp.jmp_64_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 01/23/2023] Open
Abstract
INTRODUCTION Image quality of digital mammography system is generally defined by three primary physical parameters, namely, contrast, resolution, and noise. Quantification of these metrics can be done by measuring objective image quality parameters defined as contrast-to-noise ratio (CNR), modulation transfer function (MTF), and noise power spectra (NPS). MATERIALS AND METHODS In the present study, various imaging metrics such as CNR, contrast detail resolution, MTF, and NPS were evaluated for a direct flat-panel detector-based digital mammography system following the European Guidelines. Furthermore, system performance relating to both image quality and doses were evaluated using figure of merit (FOM) in terms of CNR2/mean glandular dose (MGD) under automatic exposure control (AEC) and clinically used OPDOSE operating mode. RESULTS AND CONCLUSION Under AEC mode, FOM values for the 4.5 cm thick BARC polymethyl methacrylate (PMMA) phantom were found to be 15.02, 15.88, and 19.82 at Mo/Mo, Mo/Rh, and W/Rh target/filter (T/F), respectively. Under OPDOSE mode, FOM values were found to 65.32, 11.80, and 1.14 for the BARC PMMA phantom thickness of 2, 4.5, and 8 cm, respectively. Under OPDOSE mode, the calculated MGD values for three Computerized Imaging Reference Systems slab phantoms having total thickness of 7 cm were observed to be 3.03, 2.32, and 1.75 mGy with glandular/adipose tissue compositions of 70/30, 50/50, and 30/70, respectively, whereas for the 2-8-cm thick BARC PMMA phantom, the calculated MGDs were found to be in the range of 0.57-3.32 mGy. All the calculated MGDs values were found to be lower than the acceptable level of dose limits provided in European Guidelines.
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Affiliation(s)
- Reena Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - S. D. Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - P. S. Sarkar
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
- Technical Physics Division, Bhabha Atomic Research Centre (BARC), Mumbai, Maharashtra, India
| | - D. Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
- Homi Bhabha National Institute, Mumbai, Maharashtra, India
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34
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Datta D, Krishnababu K, Stroscio MA, Dutta M. Effect of quantum confinement on lifetime of anharmonic decay of optical phonons in semiconductor nanostructures. J Phys Condens Matter 2018; 30:355302. [PMID: 29972139 DOI: 10.1088/1361-648x/aad104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The anharmonic decay of phonons underlies many important effects in semiconductors, e.g. hotspot formation, phonon bottleneck and thermal resistivity. In this article, we evaluate the effect of quantum confinement on the anharmonic decay transition probability in a cubic isotropic material. This article focuses on the anharmonic decay of longitudinal optical phonons, generated from hot electrons, are directly related to formation of hotspots in the active region of semiconductor devices. The confinement effect has been realized in double interface heterostructure quantum well (DHSQW) (e.g. AlAs/GaAs/AlAs) and free-standing quantum well (FSQW) (e.g. GaAs) structures as the confined phonon modes have different properties inside the structures. The longitudinal-optical phonon decay rate is reduced for the case of a DHSQW compared to bulk material and for a FSQW the decay rate has a strong dependence on wavevector value of the three phonons involved.
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Affiliation(s)
- D Datta
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL, United States of America
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35
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Madhumita B, Sneha C, Dipali V, Pradhan SM, Bakshi AK, Datta D, Tripathi SM, Singh SK. DEVELOPMENT OF AN ALGORITHM TO ESTIMATE EYE LENS DOSE IN TERMS OF OPERATIONAL QUANTITY Hp(3) USING HEAD TLD BADGE. Radiat Prot Dosimetry 2018; 178:364-373. [PMID: 28981726 DOI: 10.1093/rpd/ncx123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
In view of the recommendations of International Commission on Radiological Protection for reduction of the occupational annual dose limit for eye lens from 150 mSv to 20 mSv/y, questions have been raised on the adequacy of monitoring for the quantities Hp(10) and Hp(0.07). As an immediate requirement, in the present situation, where there is no exclusive eye lens dosemeter in India, the existing chest TLD badge was modified to be used as head badge (head dosemeter) by including a strap to enable wearing on the forehead. In order to estimate the eye lens dose in terms of the operational quantity Hp(3), the prevalent algorithm of chest badge was also modified. The modified algorithm was applied to estimate Hp(3) for dosemeters irradiated to various beta and photon radiations including mixtures. The Q values (estimated/delivered dose equivalent) were found to be within ±20% for most of the photon beams.
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Affiliation(s)
- B Madhumita
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - C Sneha
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - V Dipali
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - S M Pradhan
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - A K Bakshi
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic and Research Centre (BARC), Mumbai 400085, India
| | - S M Tripathi
- Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - S K Singh
- Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400085, India
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36
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Selvam TP, Chattaraj A, Datta D. FLUKA-BASED MONTE CARLO INVESTIGATION OF MICRODOSIMETRIC DISTRIBUTIONS OF TELECOBALT BEAM. Radiat Prot Dosimetry 2018; 178:430-440. [PMID: 29036422 DOI: 10.1093/rpd/ncx182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
FLUKA-based Monte Carlo calculations of microdosimetric distributions in water phantom involving a walled spherical Tissue-Equivalent Proportional Counter filled with tissue-equivalent propane gas have been studied for an indigenously developed telecobalt machine. The simulated site size considered in the study was 2 μm. In the Monte Carlo calculations, field size was varied from 10 cm × 10 cm to 35 cm × 35 cm and the depth was varied as 5-20 cm. The study also includes calculation of microdosimetric distributions with a 30° wedge filter. The efficiency of the calculations was improved up to a factor of 26 by choosing appropriate cut off values for production and transport of electrons. The calculated microdosimetric distributions of telecobalt machine is distinctly different from that of a bare 60Co source which is attributed to the influence of scattered photons from the machine head and the water phantom.
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Affiliation(s)
- T Palani Selvam
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Mumbai 400094, India
| | - Arghya Chattaraj
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Mumbai 400094, India
| | - D Datta
- Radiological Physics & Advisory Division, Health, Safety & Environment Group, Bhabha Atomic Research Centre, Mumbai 400094, India
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Rakesh RB, Kumar M, Sneha C, Ratna P, Datta D. BETA DOSE EVALUATION ALGORITHM FOR CaSO4:Dy BASED TLD BADGE USED IN COUNTRYWIDE PERSONNEL MONITORING PROGRAMME IN INDIA. Radiat Prot Dosimetry 2018; 178:342. [PMID: 28981805 DOI: 10.1093/rpd/ncx118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- R B Rakesh
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - Munish Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - C Sneha
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - P Ratna
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
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38
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Kumar M, Datta D. Comments on "Radiological Risk Assessment of Cosmic Radiation at Aviation Altitudes (A Trip from Houston Intercontinental Airport to Lagos International Airport)". J Med Phys 2018; 42:279-280. [PMID: 29296044 PMCID: PMC5744458 DOI: 10.4103/jmp.jmp_55_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Munish Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
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39
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Sahai MK, Pradhan SM, Bakshi AK, Datta D. Study of Residual TL of CaSO4:Dy-based Thermoluminescence Dosemeter. Radiat Prot Dosimetry 2017; 177:342-347. [PMID: 28453832 DOI: 10.1093/rpd/ncx052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 04/04/2017] [Indexed: 06/07/2023]
Abstract
Thermoluminescence (TL) signal obtained during second readout of a TL dosemeter disc previously exposed to ionising radiation is termed as residual TL. The origin of residual TL has not been discussed in detail so far in the literature. In this work, experimentally obtained residual TL signal and its origin is studied for CaSO4:Dy-based TL dosemeter through numerical simulation and role of deeper traps has been discussed.
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Affiliation(s)
- Manish K Sahai
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 094, India
| | - S M Pradhan
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 094, India
| | - A K Bakshi
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 094, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 094, India
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Srivastava K, Soin S, Sapra BK, Ratna P, Datta D. FEASIBILITY STUDY FOR IDENTIFICATION OF STATIC AND DYNAMIC EXPOSURE USING CCD IMAGING TECHNIQUE FOR Caso4:Dy TL DOSEMETERS. Radiat Prot Dosimetry 2017; 176:309-315. [PMID: 28338940 DOI: 10.1093/rpd/ncx011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 01/25/2017] [Indexed: 06/06/2023]
Abstract
The occupational exposure incurred by the radiation workers due to the external radiation is estimated using personal dosemeter placed on the human body during the monitoring period. In certain situations, it is required to determine whether the dosemeter alone was exposed accidentally/intentionally in radiation field (static exposure) or was exposed while being worn by a worker moving in his workplace (dynamic exposure). The present thermoluminscent (TL) based personnel monitoring systems are not capable of distinguishing between the above stated (static and dynamic) exposure conditions. The feasibility of a new methodology developed using the charge coupled device based imaging technique for identification of the static/dynamic exposure of CaSO4:Dy based TL detectors for low energy photons has been investigated. The techniques for the qualitative and the quantitative assessments of the exposure conditions are presented in this paper.
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Affiliation(s)
- Kshama Srivastava
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai-40085, India
| | - Seepika Soin
- Industrial Plants Safety Division, Atomic Energy Regulatory Board, Mumbai-40094, India
| | - B K Sapra
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai-40085, India
| | - P Ratna
- Radiological Safety Division, Atomic Energy Regulatory Board, Mumbai-40094, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai-40085, India
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Singh M, Mukhopadhyay D, Datta D. A numerical methodology for estimation of volatile fission products release from nuclear fuel. Nuclear Engineering and Design 2017. [DOI: 10.1016/j.nucengdes.2017.02.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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42
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Kumar M, Bakshi AK, Rakesh RB, Ratna P, Kulkarni MS, Datta D. DEEP, SHALLOW AND EYE LENS DOSES FROM 106Ru/106Rh-A COMPARSION. Radiat Prot Dosimetry 2017; 176:211-216. [PMID: 28115659 DOI: 10.1093/rpd/ncw383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/20/2016] [Indexed: 06/06/2023]
Abstract
106Ru/106Rh is unique amongst other commonly used beta sources such as 147Pm, 85Kr, 204Tl, 32P, natU and 90Sr/90Y in the sense that it is capable of simultaneously delivering shallow/skin, eye lens and deep/whole body doses (WBDs) and they differ from each other substantially. In view of this, the investigation of various quantities defined for individual monitoring is possible and this makes 106Ru/106Rh beta source, a classical example in radiation protection and dosimetry. This led us to estimate skin, eye lens and WBDs for 106Ru/106Rh beta source. Optically stimulated luminescence based ultra-thin α-Al2O3:C disc dosimeters were used in the present study. Typical values (relative) of the eye lens and whole body/deep doses with respective to the skin dose (100%) were experimentally measured as ~66 ± 4.6% and 17 ± 3.9%, respectively. The study shows that 106Ru/106Rh beta source is capable of delivering even WBD which is not the case with other beta sources.
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Affiliation(s)
- Munish Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - A K Bakshi
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - R B Rakesh
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - P Ratna
- Operating Plant Safety Division, Atomic Energy Regulatory Board, Mumbai 400 094, India
| | - M S Kulkarni
- Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
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Ralph A, Ashfield-Watt P, Haralambos K, Datta D, McDowell I. A comparison of scoring criteria for the prediction of mutations for Familial Hypercholesterolaemia (FH) in a cohort of Welsh lipid index patients and family relatives. ATHEROSCLEROSIS SUPP 2017. [DOI: 10.1016/j.atherosclerosissup.2017.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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44
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Haralambos K, Payne J, Datta D, McDowell I, Cramb R, Williams S, Cather M, Neely D, Soran H, Miedzybroadzka Z, Whitmore J, Williams M, Humphries S. How many patients with a monogenic diagnosis of Familial Hypercholesterolemia are currently known in UK lipid clinics? ATHEROSCLEROSIS SUPP 2017. [DOI: 10.1016/j.atherosclerosissup.2017.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Chatterjee S, Banerjee K, Pandit D, Roy P, Bandyopadhyay T, Ravishankar R, Bhattacharya C, Bhattacharya S, Datta D, Banerjee SR. Optimization of beam dump shielding for K-130 cyclotron at VECC. Appl Radiat Isot 2017; 128:216-223. [PMID: 28738250 DOI: 10.1016/j.apradiso.2017.07.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 06/21/2017] [Accepted: 07/13/2017] [Indexed: 11/18/2022]
Abstract
A compact and efficient beam dump shield has been designed using Monte Carlo simulation code FLUKA to facilitate low background measurement of neutron and gamma rays using K130 cyclotron at Variable Energy Cyclotron Centre, Kolkata (VECC). Iron, lead and high density Polyethylene (HDPE) were considered in the design of the beam dump shield. Representative FLUKA simulation results have been validated using in-beam experiment performed on the same beam dump constituents. Experimental neutron and gamma-rays energy spectra have been found to be in fair agreement with the simulation results. Activation of various beam dump shield components were also carried out.
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Affiliation(s)
- S Chatterjee
- HS&E Group, Bhabha Atomic Research Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India.
| | - K Banerjee
- Variable Energy Cyclotron Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India
| | - Deepak Pandit
- Variable Energy Cyclotron Centre, Kolkata 700064, India
| | - Pratap Roy
- Variable Energy Cyclotron Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India
| | - T Bandyopadhyay
- HS&E Group, Bhabha Atomic Research Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India
| | - R Ravishankar
- HS&E Group, Bhabha Atomic Research Centre, Kolkata 700064, India
| | - C Bhattacharya
- Variable Energy Cyclotron Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India
| | | | - D Datta
- HS&E Group, Bhabha Atomic Research Centre, Mumbai 400094, India; Homi Bhabha National Institute, Mumbai 400085, India
| | - S R Banerjee
- Variable Energy Cyclotron Centre, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai 400085, India
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46
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Kumar R, Amols HI, Lovelock M, Sharma SD, Datta D. Quick, efficient and effective patient-specific intensity-modulated radiation therapy quality assurance using log file and electronic portal imaging device. J Cancer Res Ther 2017. [PMID: 28643751 DOI: 10.4103/jcrt.jcrt_1045_16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM The aim of work is to explore a quick, efficient, and effective patient-specific intensity-modulated radiation therapy (IMRT) quality assurance (QA). MATERIALS AND METHODS Software tools were developed to extract and analyze the multi-leaf collimator (MLC) leaf positions (LPs) from electronic portal imaging device (EPID) images for Varian C-series machine and TrueBeam, to extract useful data from MLC log file of C-series linear accelerator (LINAC), to extract useful information from the trajectory log binary file of TrueBeam LINAC, to compare LPs derived from EPID images with log file/trajectory log data, and to analyze IMRT treatment files using the MATLAB programming language. The difference in LP determined from the trajectory log and EPID images was proposed for patient-specific QA. RESULTS It was found that the differences in LP for regular radiation fields generated using stationary leaves are <0.5 mm for all the field sizes while for regular radiation fields generated using the moving leaves are more but <2 mm. The differences in LPs for IMRT field were also determined and found to be <2 mm. CONCLUSIONS The methodology demonstrated can be used for establishing the accuracy of trajectory log data and for independent routine IMRT QA by generating single number like gamma index to indicate pass or fail of an IMRT treatment plan. The QA indices such as numbers of occurrences of ≥2 mm error in LPS are found more than 5% of total number of occurrences; the dosimetric review of planned treatment is advisable.
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Affiliation(s)
- Rajesh Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Mumbai, Maharashtra, India
| | - H I Amols
- Department of Medical Physics, Ex-Memorial Sloan Kettering Cancer Centre, New York, USA
| | - M Lovelock
- Department of Medical Physics, Memorial Sloan Kettering Cancer Centre, New York, USA
| | - S D Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Mumbai, Maharashtra, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CTCRS, Mumbai, Maharashtra, India
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Rakesh RB, Kumar M, Sneha C, Ratna P, Datta D. BETA DOSE EVALUATION ALGORITHM FOR CaSO4:Dy BYSED TLD BADGE USED IN COUNTRYWIDE PERSONNEL MONITORING PROGRAMME IN INDIA. Radiat Prot Dosimetry 2017; 175:96-103. [PMID: 27765890 DOI: 10.1093/rpd/ncw273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
The prevalent algorithm for the estimation of beta dose, which in turn is used for estimation of skin dose for exposures involving beta radiations was observed to significantly overestimate the dose in individual monitoring based on CaSO4:Dy TLD badge in India. A new algorithm has been developed by estimating the correction factor from the response of dosemeter to different beta sources at various angles of incidence. The correction factor was observed to vary linearly with the ratio of the responses of dosemeter element without filter (D3) and dosemeter element under Perspex filter (D2). The correction factor determined using the ratio of D3 and D2 was applied to the response (D3) of dosemeter element without filter for estimation of beta dose. Protocol for identification of beta in the mixed gamma beta fields was defined such that it resulted in nearly same correction factor for given beta source in both gamma beta mixed fields and pure beta fields. The beta dose evaluation algorithm has provided the beta dose estimation within the required accuracy for >90% cases obtained from national quality assurance test data from different laboratories.
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Affiliation(s)
- R B Rakesh
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - Munish Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - C Sneha
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - P Ratna
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre (BARC), Mumbai 400 085, India
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Allen L, Datta D, Speight L, Ketchell R, Lau D, Duckers J. 289 Routinely testing serum magnesium in acute admissions to the All Wales Adult CF Centre (AWACFC) – are we doing the right thing? J Cyst Fibros 2017. [DOI: 10.1016/s1569-1993(17)30628-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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49
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Akhilesh P, Kulkarni AR, Jamhale SH, Sharma SD, Kumar R, Datta D. Estimation of Eye Lens Dose During Brain Scans Using Gafchromic Xr-QA2 Film in Various Multidetector CT Scanners. Radiat Prot Dosimetry 2017; 174:236-241. [PMID: 27247444 DOI: 10.1093/rpd/ncw132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/06/2016] [Indexed: 06/05/2023]
Abstract
The purpose of this study was to estimate eye lens dose during brain scans in 16-, 64-, 128- and 256-slice multidetector computed tomography (CT) scanners in helical acquisition mode and to test the feasibility of using radiochromic film as eye lens dosemeter during CT scanning. Eye lens dose measurements were performed using Gafchromic XR-QA2 film on a polystyrene head phantom designed with outer dimensions equivalent to the head size of a reference Indian man. The response accuracy of XR-QA2 film was validated by using thermoluminescence dosemeters. The eye lens dose measured using XR-QA2 film on head phantom for plain brain scanning in helical mode ranged from 43.8 to 45.8 mGy. The XR-QA2 film measured dose values were in agreement with TLD measured dose values within a maximum variation of 8.9%. The good correlation between the two data sets confirms the viability of using XR-QA2 film for eye lens dosimetry.
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Affiliation(s)
- Philomina Akhilesh
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT&CRS Building, Anushaktinagar, Mumbai 400094, India
| | - Arti R Kulkarni
- Radiological Safety Division, Atomic Energy Regulatory Board, Niyamak Bhavan, Anushaktinagar, Mumbai 400094, India
| | - Shramika H Jamhale
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT&CRS Building, Anushaktinagar, Mumbai 400094, India
| | - S D Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT&CRS Building, Anushaktinagar, Mumbai 400094, India
| | - Rajesh Kumar
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT&CRS Building, Anushaktinagar, Mumbai 400094, India
| | - D Datta
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, CT&CRS Building, Anushaktinagar, Mumbai 400094, India
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Srivastava K, Bakshi AK, Punekar MP, Kolambe DH, Ratna P, Datta D. Overview of the Quality Assurance Programme Implemented for TLD Based Individual Monitoring in India. Radiat Prot Dosimetry 2017; 174:175-184. [PMID: 27150519 DOI: 10.1093/rpd/ncw108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
The effective implementation of a comprehensive quality assurance (QA) programme in any individual monitoring service plays a key role in attaining and sustaining the level of performance at par with international standards. In India, individual monitoring of more than 120 000 radiation workers is provided through 16 laboratories using a CaSO4:Dy based thermoluminescence dosimetry (TLD) badge system. In such a wide-spread programme, the harmonization of procedures and regular QA check on the dosimetry system are utmost important to ensure the uniform standard of accuracy and reliability of the service. This paper discusses some aspects of the QA programme implemented at different stages of the TLD monitoring system and provides the results of the performance test of monitoring laboratories.
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Affiliation(s)
- Kshama Srivastava
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - A K Bakshi
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - M P Punekar
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - D H Kolambe
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - P Ratna
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - D Datta
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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