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F.-U.-Z. Chowdhury

Bio: F.-U.-Z. Chowdhury is an academic researcher from Chittagong University of Engineering & Technology. The author has contributed to research in topics: Ferrite (magnet) & Dielectric. The author has an hindex of 12, co-authored 45 publications receiving 515 citations. Previous affiliations of F.-U.-Z. Chowdhury include Bangladesh University & Bangladesh University of Engineering and Technology.

Papers
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TL;DR: In this paper, four branded glass samples of different thickness and color were analyzed for shielding and dosimetric properties, and the chemical composition of the studied material was evaluated by EDX technique.
Abstract: Following the rapid growing economy, the Bangladeshi dwellers are replacing their traditional (mud-, bamboo-, and wood-based) houses to modern multistoried buildings, where different types of glasses are being used as decorative as well as structural materials due to their various advantageous properties. In this study, we inquire the protective and dosimetric capability of commercial glasses for ionizing radiation. Four branded glass samples (PHP-Bangladesh, Osmania-Bangladesh, Nasir-Bangladesh, and Rider-China) of same thickness and color but different elemental weight fractions were analyzed for shielding and dosimetric properties. The chemical composition of the studied material was evaluated by EDX technique. A well-shielded HPGe γ-ray spectrometer combined with associated electronics was used to evaluate the attenuation coefficients of the studied materials for 59 keV, 661 keV, 1173 keV and 1332 keV photon energies. A number of shielding parameters- half value layer (HVL), radiation protection efficiency (RPE) and effective atomic number (Zeff) were also evaluated. The data were compared with the available literature (where applicable) to understand its shielding capability relative to the standard materials such as lead. Among the studied brands, Rider (China) shows relatively better indices to be used as ionizing radiation shielding material. The obtained, Zeff of the studied glass samples showed comparable values to the TLD-200 dosimeter, thus considered suitable for environmental radiation monitoring purposes.

138 citations

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TL;DR: In this paper, a wet chemical co-precipitation method has been used to synthesize chitosan-coated Co1−xMnxFe2O4 (0.8Mn0.2) nano ferrites.

71 citations

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TL;DR: In this article, four popular brands of window glass are investigated, all available within the local market (PHP-Bangladesh, Usmania, Nasir and Rider-China), all with the same thickness and colour, varying in terms of elemental weight fractions as evaluated by energy dispersive X-ray analysis.
Abstract: One sign of a vibrant Bangladeshi economy has been the move away from the use of more traditional housing materials towards a preference for modern constructional media. Glass, one such example, used both decoratively and in a structural context, offers various advantageous properties and facets including a protective feature against radiation that has not previously been considered. Current interest examines the dosimetric possibilities offered by the commercial glass as a secondary shield and also in retrospective ionising radiation exposure analysis. Four popular brands of window glass are investigated, all available within the local market (PHP-Bangladesh, Usmania-Bangladesh, Nasir-Bangladesh and Rider-China), all with the same thickness and colour, varying in terms of elemental weight fractions as evaluated by energy dispersive X-ray analysis. As potential attenuators of transmitted radiation thereby forming secondary barriers against radiation exposure from penetrating radiations, the four b...

65 citations

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TL;DR: In this article, the structural and electrical properties of Ni-Zn ferrites have been investigated by the X-ray diffraction (XRD), scanning electron microscopy (SEM), DC resistivity and dielectric measurements.

59 citations

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TL;DR: In this paper, structural properties, impedance, dielectric and electric modulus spectra have been used to investigate the sintering temperature (T s ) effect on the single phase cubic spinel Ni 0.6 Zn 0.4 Fe 2 O 4 (NZFO) ceramics synthesized by standard ceramic technique.
Abstract: Structural properties, impedance, dielectric and electric modulus spectra have been used to investigate the sintering temperature ( T s ) effect on the single phase cubic spinel Ni 0.6 Zn 0.4 Fe 2 O 4 (NZFO) ceramics synthesized by standard ceramic technique. Enhancement of dielectric constants is observed with increasing T s . The collective contribution of n-type and p-type carriers yields a clear peak in notable unusual dielectric behavior is successfully explained by the Rezlescu model. The non-Debye type long range dielectric relaxation phenomena is explained by electric modulus formalism. Fast response of the grain boundaries of the sample sintered at lower T s sample leading to small dielectric spin relaxation time, t (several nanoseconds) have been determined using electric modulus spectra for the samples sintered at different T s . Two clear semicircles in impedance Cole-Cole plot have also been successfully explained by employing two parallel RC equivalent circuits in series configuration taking into account no electrode contribution. Such a long relaxation time in NZFO ceramics could suitably be used in nanoscale spintronic devices.

41 citations


Cited by
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TL;DR: Several reaction mechanisms have been proposed for the formation of plasma polymers, such as monomer fragmentation followed by poly-recombination into randomly structured and crosslinked films; fragmentation, accompanied by formation of acetylene or other film-forming intermediates and deposition of polystyrene-like material; plasma-initiation of a radical chain-growth polymerization; and ion-molecule reactions, as well as ionic chain growth polymerization as discussed by the authors.
Abstract: Several reaction mechanisms have been proposed for the formation of plasma polymers, such as monomer fragmentation followed by poly-recombination into randomly structured and crosslinked films; fragmentation, accompanied by the formation of acetylene or other film-forming intermediates and deposition of polystyrene-like material; plasma-initiation of a radical chain-growth polymerization; and ion-molecule reactions, as well as ionic chain-growth polymerization. The bulk structure of plasma polymers is completely irregular, far from that of conventional polymers. The retention of functional groups during plasma polymerization tends to be greater than that of the entire monomer structure found again as an intact repeat unit in the resulting plasma polymer. An alternative method for depositing ultra-thin, pin-hole free coatings, ones that possess regular structures, is by electrospray ionization (ESI) of pre-fabricated polymers.

344 citations

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TL;DR: A review paper on the major researches in the field of nickel ferrites on one platform is presented in this paper, where the major research findings are tabulated and briefly summarized.

170 citations

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TL;DR: In this paper, the authors reviewed the CoFe2O4 nanoparticles doped with various elements and their applications in various fields, including permanent magnets, magnetic recorders in high-density and micro-wave devices, and magnetic fluids.

140 citations

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TL;DR: In this article, the structural changes of polyaniline upon doping and the reduction of optical bandgap are explained on the basis of the results obtained from FTIR spectroscopic and UV-VIS absorption studies.
Abstract: Pure and iodine-doped polyaniline thin films are prepared by ac plasma polymerization technique. Doping of iodine is carried out in situ as well as by employing iodine chamber methods. The structural analyses of pure and iodine-doped polyaniline thin films are carried out by FTIR spectroscopic studies. Optical bandgaps of these films are evaluated from UV-VIS absorption studies. Direct and indirect transition energy gaps are determined from Tauc plots. The structural changes of polyaniline upon doping and the reduction of optical bandgap are explained on the basis of the results obtained from FTIR spectroscopic and UV-VIS absorption studies.

122 citations

Journal ArticleDOI
TL;DR: In this article, a detailed investigation on the radiation shielding features of TeO2-B2O3-Bi2O 3-LiF-SrCl2 glass system is presented.

113 citations