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Variation of radon concentrations in soil and groundwater and its correlation with radon exhalation rate from soil in Budhakedar,Garhwal Himalaya
No full textRadon was measured in soil-gas and groundwater in the Budhakedar area of
Tehri Garhwal, India in summer and winter to obtain the seasonal variation and its
correlation with radon exhalation rate. The environmental surface gamma dose rate
was also measured in the same area. The radon exhalation rate in the soil sample
collected from different geological unit of Budhakedar area was measured using
plastic track detector (LR-115 type II) technique. The variation in the radon
concentration in soil-gas was found to vary from 1098 to 31,776 Bq.m–3 with an
average of 7456 Bq.m–3 in summer season and 3501 to 42883 Bq.m–3 with an average of
17148 Bq.m–3 in winter season. In groundwater, it was found to vary from 8 to 3047
Bq.l–1 with an average value 510 Bq.l–1 in summer and 26 to 2311 Bq.l–1 with an
average value 433 Bq.L–1 in winter. Surface gamma dose rate in the study area varied
from 32.4 to 83.6 .R.h–1 with an overall mean of 58.7 .R.h–1 in summer and 34.6 to
79.3 .R.h–1 with an average value 58.2 .R.h–1 in winter. Radon exhalation rate from
collected soil samples was found to vary from 0.1 × 10–5 to 5.7 × 10–5 Bq.kg–1.h–1
with an average of 1.5 × 10–5 Bq.kg–1.h–1 in summer season and 1.7 × 10–5 to 9.6 ×
10–5 Bq.kg–1.h–1 with an average of 5.5 × 10–5 Bq.kg–1.h–1. A weak negative
correlation was observed between radon exhalation rate from soil and radon
concentration in the soil. Radon exhalation rate from the soil was also not found to
be correlated with the gamma dose rate, while it shows a positive correlation with
radon concentration in water in summer season. Inter-correlations among various
parameters are discussed in detail.Variation of radon concentrations in soil and groundwater and its correlation with
radon exhalation rate from soil in Budhakedar,Garhwal Himalaya
Ganesh Prasad, Yogesh Prasad, G S Gusain, Manjari Badoni, J M S Rana and R C Ramola*
Department of Physics, H N B Garhwal University, Badshahi Thaul Campus,
Tehri Garhwal-249 199, Uttarakhand, India
E-mail : [email protected] of Physics, H N B Garhwal University, Badshahi Thaul Campus,
Tehri Garhwal-249 199, Uttarakhand, Indi
Preparation and studies of electrical properties of cobalt substituted Li-Zn ferrites by sol-gel auto combustion method
No full textA series of Co substituted lithium zinc ferrite powders with different
content of Co (0.00 to 0.1 in steps of 0.02) were prepared by a novel sol-gel auto
combustion process using citric acid. Their spinel structure was confirmed by XRD.
The variation in lattice parameter and density with cobalt concentration was studied
which showed an increasing trend. A decreasing pattern was observed in variation of
porosity with increasing Co. Room temperature dielectric constant and resistivity
were studied as a function of composition at 10 KHz. The room temperature dielectric
constant decreases with successive addition of Co2+ in the series. The observed
variation in dielectric constant has been explained on the basis of space charge
polarization and Koops two layer model. Resistivity is observed to increase with
increasing concentration and the observed variation in resistivity has been
explained by Verwey hopping mechanism.Author Affiliation: Ibetombi Soibam1, Sumitra Phanjoubam1, H B Sharma1, H N K Sarma1
and Chandra Prakash2
1Department of Physics, Manipur University, Canchipur, Imphal-795 003, Manipur, India
2Directorate of ER & IPR, DRDO Bhawan, Rajaji Marg, New Delhi-110 011, India
E-mail : [email protected] of Physics, Manipur University, Canchipur, Imphal-795 003, Manipur, India
2Directorate of ER & IPR, DRDO Bhawan, Rajaji Marg, New Delhi-110 011, Indi
SHI induced nano track polymer filters and characterization
No full textSwift heavy ion irradiation produces damage in polymers in the form of latent tracks. Latent
tracks can be enlarged by etching it in a suitable etchant and thus nuclear track etch membrane can be formed
for gas permeation / purification in particular for hydrogen where the molecular size is very small. By applying
suitable and controlled etching conditions well defined tracks can be formed for specific applications of the
membranes. After etching gas permeation method is used for characterizing the tracks. In the present work
polycarbonate (PC) of various thickness were irradiated with energetic ion beam at Inter University Accelerator
Centre (IUAC), New Delhi. Nuclear tracks were modified by etching the PC in 6N NaOH at 60 (±1) oC from both
sides for different times to produce track etch membranes. At critical etch time the etched pits from both the sides
meet a rapid increase in gas permeation was observed. Permeability of hydrogen and carbon dioxide has been
measured in samples etched for different times. The latent tracks produced by SHI irradiation in the track etch
membranes show enhancement of free volume of the polymer. Nano filters are separation devices for the
mixture of gases, different ions in the solution and isotopes and isobars separations. The polymer thin films with
controlled porosity finding it self as best choice. However, the permeability and selectivity of these polymer
based membrane filters are very important at the nano scale separation. The Swift Heavy Ion (SHI) induced
nuclear track etched polymeric films with controlled etching have been attempted and characterized as nano
scale filters.E-mail : [email protected] of Physics, University of Rajasthan,Jaipur-302 004, Indi
Different shapes of tracks in phlogopite, biotite and soda lime glass
No full textEtched track opening geometries in Biotite, Phlogopite and soda-lime glass irradiated with swift
heavy ions [197Au(11.64 MeV/n), 136Xe(11.56 MeV/n), 58Ni(11.56 MeV/n)] at different angle of incidence have
been studied using appropriate chemical etching technique. Different geometries (Hexagonal, irregular polygon,
triangular in case of Biotite and Phlogopite, and circular & elliptical in case of soda lime glass detector) of heavy
ion tracks are reported in the present investigations using optical microscope. The different shapes of these
heavy ions track geometries are found to be related with various target-projectile parameters (viz : type of
projectiles, energy, stopping power, angle of incidence of the projectile, density of defects and its reactivity with
etchant, etching conditions and chemical structure of the detectors). The dependence of different shapes of
heavy ion tracks in isotropic and anisotropic medium on the variation of radiation damage densities along the ion
trajectories have also been discussed in the present paper.Author Affiliation: Mohan Singh, Lakhwant Singh and Bikram Singh
1.Department of Physics, Guru Nanak Dev University,
Amritsar-143 005, India
E-mail : [email protected] of Physics, Guru Nanak Dev University,
Amritsar-143 005, Indi
Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp
No full textThe calcium aluminates doped with Eu ions, Ca5Al8O14 : Eu, phosphors are prepared by the
combustion method. The formation of crystalline aluminates was confirmed by X-ray diffraction pattern. The
prepared phosphors were characterized by SEM, TGA, DTA, particle size analyzer and Photoluminescence (PL)
techniques. From the UV-excited luminescence spectra it was found that the Eu ions acts as a luminescent
centre with luminescence at the blue (λmax = 470 nm) region due to 4f 65d1 → 4f 7 transition. The excitation
spectra show the broad band at 355 nm wavelength (λem = 470 nm). The excitation 355 nm is a mercury free
excitation and therefore Ca5Al8O14 : Eu may be useful for the solid state lighting phosphor in lamp industry.Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp
Abhay D Deshmukh1*, S J Dhoble1, S V Godbole2, M K Bhide2 and D R Peshwe3
1Kamla Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India
2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre,
Mumbai-400 085, India
3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011,
Maharashtra, India
E-mail : [email protected] Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India
2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre,
Mumbai-400 085, India
3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011,
Maharashtra, Indi
Semiconductor magnetism : excitements and promises
No full textBeginning from a historical introduction, we present in this article the
current excitements resulting from a possible hybridization of the two important
areas of Condensed Matter Physics, namely, semiconductors and magnetism. Both the
subjects have contributed to economically important technologies and rich physics,
independently. We discuss the physics of diluted magnetic semiconductors (DMS) with
special emphasis on the theory of light induced magnetism (LIM), keeping in mind
both narrow gap and wide gap DMS.Semiconductor magnetism : excitements and promises
G S Tripathi
Department of Physics, Berhampur University, Berhampur-760 007, Orissa, India
E-mail : [email protected] of Physics, Berhampur University, Berhampur-760 007, Orissa, Indi
Theoretical description of ABO3 relaxor ferroelectric : A review
No full textSignificant similarities exist between spin glasses and relaxor
ferroelectric. Because of the wealth of available knowledge both in experimental and
theoretical aspects in the former, attempt has been made by many workers to deal the
relaxor behavior in analogy with the spin glasses. However, the nature of diffused
phase transition in relaxor ferroelectric remains controversial. To overcome this
difficulty, many workers extended the above model to a new type of dipolar glasses,
namely spherical vector glasses in which order parameter field is described as a
continuous vector field of variable length instead of fixed length as proposed
earlier. The present review is aimed to focus on all the models.Theoretical description of ABO3 relaxor ferroelectric :
A review
M R Panigrahi, T Badapanda and S Panigrahi*
Department of Physics, National Institute of Technology, Rourkela-769 008, Orissa,
India
E-mail : [email protected] of Physics, National Institute of Technology, Rourkela-769 008, Orissa,
Indi
Thermal and optical properties of electron beam irradiated cellulose triacetate
No full textSamples from Cellulose triacetate (CTA) sheets were irradiated with
electron beam in the dose range 10–200 kGy. Non-isothermal studies were carried out
using thermogravimetric analysis (TGA) to obtain the activation energy of thermal
decomposition for CTA polymer. The CTA samples decompose in one main break down
stage. The results indicate that the irradiation by electron beam in the dose range
80–200 kGy increases the thermal stability of the polymer samples. Also, the
variation of melting temperatures with the electron dose has been determined using
differential thermal analysis (DTA). The CTA polymer is characterized by the
appearance of one endothermic peak due to melting. It is found that the irradiation
in the dose range 10–80 kGy causes defects generation that splits the crystals
depressing the melting temperature, while at higher doses (80–200 kGy), the
thickness of crystalline structure (lamellae) is increased, thus the melting
temperature increases. In addition, the transmission of these samples in the
wavelength range 200–2500 nm, as well as any color changes, were studied. The color
intensity .E* was greatly increased on increasing the electron beam dose, and
accompanied by a significant increase in the blue color component.Thermal and optical properties of electron beam irradiated cellulose triacetate
S A Nouh1*, Amal Mohamed2 and H M El Hussieny1
1Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
2Department of Physics, Faculty of Science, Zagazig University, Cairo, Egypt
E-mail : [email protected] of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
2Department of Physics, Faculty of Science, Zagazig University, Cairo, Egyp
Estimate of etched tracks by optical method and spark counting
No full textSolid State Nuclear Track Detectors (SSNTD) are commonly used for long
term measurements of radon, thoron and progeny concentrations. In the present study,
we compared the optical counting method and the spark counting technique for
counting the alpha tracks on LR 115 track detector films. The paper discusses the
various parameters that are innate in the process. More than 300 films were counted
by both optical microscope and spark counter and the results are compared. The
overall results show that the tracks obtained by spark counting are marginally less
compared to the optical measurement. A linear fit of the data gives a slope less
that one, which indicates that both the methods are almost in good agreement for
counting the tracks when the track density is low. At higher track densities the
spark counter gives an underestimation with respect to actual number of tracks
formed, which could be corrected using a relation obtained between the tracks
measured by optical method and spark counting.Estimate of etched tracks by optical method and spark counting
Rajesh Kumar, K P Eappen*, A K Shukla, R M Tripathi and V D Puranik
Environmental Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085,
India
E-mail : [email protected] Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085,
Indi
Report of the Indian Association for the Cultivation of Science for the year 2009-2010
No full textIACS Annual Report contains the yearly proceedings of the each division of the Association for the year 2009-2010IAC