Atmospheric aerosols play an important role in local, regional meteorology, visibility, air pollu... more Atmospheric aerosols play an important role in local, regional meteorology, visibility, air pollution, haze formation and energy balance of radiation. These processes influence the climate directly or indirectly. Therefore, for increasing importance of aerosols in understanding the various environmental processes and public health; it is necessary to have accurate physical and chemical identification of these aerosols. The Raman scattering has only recently been demonstrated as potential analytical method for chemical identification of aerosol particles [1], [2]. This technique is used for the chemical identification of aerosol at Ahmednagar (INDIA). Various spectroscopic techniques have been applied for the identification of the matter, while most of these techniques can be adopted as a routine analytical procedures for bulk samples. They may not be practical for aerosol samples at all. Each of these techniques has its advantages and disadvantages. For in situ identification of aer...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
ABSTRACT For the production of a clinical 15 MeV photon beam, the design of accelerator head asse... more ABSTRACT For the production of a clinical 15 MeV photon beam, the design of accelerator head assembly has been optimized using Monte Carlo based FLUKA code. The accelerator head assembly consists of e–γ target, flattening filter, primary collimator and an adjustable rectangular secondary collimator. The accelerators used for radiation therapy generate continuous energy gamma rays called Bremsstrahlung (BR) by impinging high energy electrons on high Z materials. The electron accelerators operating above 10 MeV can result in the production of neutrons, mainly due to photo nuclear reaction (γ, n) induced by high energy photons in the accelerator head materials. These neutrons contaminate the therapeutic beam and give a non-negligible contribution to patient dose. The gamma dose and neutron dose equivalent at the patient plane (SSD = 100 cm) were obtained at different field sizes of 0 × 0, 10 × 10, 20 × 20, 30 × 30 and 40 × 40 cm2, respectively. The maximum neutron dose equivalent is observed near the central axis of 30 × 30 cm2 field size. This is 0.71% of the central axis photon dose rate of 0.34 Gy/min at 1 μA electron beam current.
ABSTRACT Diffusion of lithium from a LiCl aqueous solution into polyether ether ketone (PEEK) and... more ABSTRACT Diffusion of lithium from a LiCl aqueous solution into polyether ether ketone (PEEK) and polyimide (PI) assisted by in situ irradiation with 6.5 MeV electrons was studied by the neutron depth profiling method. The number of the Li atoms was found to be roughly proportional to the diffusion time. Regardless of the diffusion time, the measured depth profiles in PEEK exhibit a nearly exponential form, indicating achievement of a steady-state phase of a diffusion–reaction process specified in the text. The form of the profiles in PI is more complex and it depends strongly on the diffusion time. For the longer diffusion time, the profile consists of near-surface bell-shaped part due to Fickian-like diffusion and deeper exponential part.
ABSTRACT Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by t... more ABSTRACT Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by the chemical coprecipitation method. These samples were irradiated with gamma radiation for the dose varying from 0.1 Gy to 50 kGy and their TL characteristics have been studied. TL dose response shows a linear behavior up to 5 kGy and further saturates with increase in the dose. A Computerized Glow Curve Deconvolution (CGCD) program was used for the analysis of TL glow curves. Trapping parameters for various peaks have been calculated by using CGCD program.
Atmospheric aerosols play an important role in local, regional meteorology, visibility, air pollu... more Atmospheric aerosols play an important role in local, regional meteorology, visibility, air pollution, haze formation and energy balance of radiation. These processes influence the climate directly or indirectly. Therefore, for increasing importance of aerosols in understanding the various environmental processes and public health; it is necessary to have accurate physical and chemical identification of these aerosols. The Raman scattering has only recently been demonstrated as potential analytical method for chemical identification of aerosol particles [1], [2]. This technique is used for the chemical identification of aerosol at Ahmednagar (INDIA). Various spectroscopic techniques have been applied for the identification of the matter, while most of these techniques can be adopted as a routine analytical procedures for bulk samples. They may not be practical for aerosol samples at all. Each of these techniques has its advantages and disadvantages. For in situ identification of aer...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
ABSTRACT For the production of a clinical 15 MeV photon beam, the design of accelerator head asse... more ABSTRACT For the production of a clinical 15 MeV photon beam, the design of accelerator head assembly has been optimized using Monte Carlo based FLUKA code. The accelerator head assembly consists of e–γ target, flattening filter, primary collimator and an adjustable rectangular secondary collimator. The accelerators used for radiation therapy generate continuous energy gamma rays called Bremsstrahlung (BR) by impinging high energy electrons on high Z materials. The electron accelerators operating above 10 MeV can result in the production of neutrons, mainly due to photo nuclear reaction (γ, n) induced by high energy photons in the accelerator head materials. These neutrons contaminate the therapeutic beam and give a non-negligible contribution to patient dose. The gamma dose and neutron dose equivalent at the patient plane (SSD = 100 cm) were obtained at different field sizes of 0 × 0, 10 × 10, 20 × 20, 30 × 30 and 40 × 40 cm2, respectively. The maximum neutron dose equivalent is observed near the central axis of 30 × 30 cm2 field size. This is 0.71% of the central axis photon dose rate of 0.34 Gy/min at 1 μA electron beam current.
ABSTRACT Diffusion of lithium from a LiCl aqueous solution into polyether ether ketone (PEEK) and... more ABSTRACT Diffusion of lithium from a LiCl aqueous solution into polyether ether ketone (PEEK) and polyimide (PI) assisted by in situ irradiation with 6.5 MeV electrons was studied by the neutron depth profiling method. The number of the Li atoms was found to be roughly proportional to the diffusion time. Regardless of the diffusion time, the measured depth profiles in PEEK exhibit a nearly exponential form, indicating achievement of a steady-state phase of a diffusion–reaction process specified in the text. The form of the profiles in PI is more complex and it depends strongly on the diffusion time. For the longer diffusion time, the profile consists of near-surface bell-shaped part due to Fickian-like diffusion and deeper exponential part.
ABSTRACT Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by t... more ABSTRACT Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by the chemical coprecipitation method. These samples were irradiated with gamma radiation for the dose varying from 0.1 Gy to 50 kGy and their TL characteristics have been studied. TL dose response shows a linear behavior up to 5 kGy and further saturates with increase in the dose. A Computerized Glow Curve Deconvolution (CGCD) program was used for the analysis of TL glow curves. Trapping parameters for various peaks have been calculated by using CGCD program.
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Papers by S. Dhole