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Peripheral blood smear analysis using image processing approach for diagnostic purposes: A review

Hegde R. B., Prasad K., Hebbar H., Sandhya I.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 3

467--480

EN

Peripheral blood smear analysis is a common practice to evaluate health status of a person. Many disorders such as malaria, anemia, leukemia, thrombocytopenia, sickle cell anemia etc., can be diagnosed by evaluating blood cells. Many groups have reported methods to automate blood smear analysis for detection of specific disorders for diagnostic purposes. In this paper,we have summarized the methods used to analyze peripheral blood smears using image processing techniques. We have categorized these methods into three groups based on approaches such as WBC analysis, RBC analysis and platelet analysis. We conclude that there is a need for a method of automation to match with human evaluation process and rule out any abnormality present in the blood smear. It is desirable for studies on automation of peripheral blood smear analysis to focus on development of robust method to handle illumination and color shade variations. Also, it is desirable to design a method which could collect all the abnormal regions from all views of a specimen to limit the manual evaluation to those regions making it more feasible for telemedicine applications.

2

Dielectric and Raman studies of Ba0.06(Na1/2Bi1/2)0.94TiO3–NaNbO3 ceramics

Roy S. K., Chaudhuri S., Kotnala R. K., Singh D. K., Singh B. P., Singh S. N., Chandra K. P., Prasad K.

Materials Science Poland

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2016

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Vol. 34, No. 2

437--445

EN

In this work the X-ray diffraction, scanning electron microscopy, Raman and dielectric studies of lead free perovskite (1 – x)Ba0.06(Na1/2Bi1/2)0.94TiO3–xNaNbO3 (0 ≤x ≤ 1.0) ceramics, prepared using a standard solid state reaction method, were investigated. X-ray diffraction studies of all the ceramics suggested the formation of single phase with crystal structure transforming from rhombohedral-tetragonal to orthorhombic symmetry with the increase in NaNbO3 content. Raman spectra also confirmed the formation of solid solution without any new phase. Dielectric studies showed that the phase transition is of diffusive character and diffusivity parameter decreases with increasing NaNbO3 content. The compositional fluctuation was considered to be the main cause of diffusivity.

3

Green synthesis and characterization of Ag1/2Al1/2TiO3 nanoceramics

Kumar S., Jha A. K., Prasad K.

Materials Science Poland

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2015

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Vol. 33, No. 1

59--72

EN

Single phase silver aluminum titanate (Ag1/2Al1/2)TiO3, later called AAT, nanoceramic powder (particle size 2 to 7.5 nm) was synthesized by a low-cost, green and reproducible tartaric acid gel process. X-ray, FT-IR, energy dispersive X-ray and high resolution transmission electron microscopy analyses were performed to ascertain the formation of AAT nanoceramics. X-ray diffraction data analysis indicated the formation of monoclinic structure having the space group P2/m(10). UV-Vis study revealed the surface plasmon resonance at 296 nm. Dielectric study revealed that AAT nanoceramics could be a suitable candidate for capacitor applications and meets the specifications for “Z7R” of Class I dielectrics of Electronic Industries Association. Complex impedance analyses suggested the dielectric relaxation to be of non-Debye type. To find a correlation between the response of the real system and idealized model circuit composed of discrete electrical components, the model fittings were performed using the impedance data. Electric modulus studies supported the hopping type of conduction in AAT. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in AAT. The ac conductivity data were used to evaluate the density of states at Fermi level and minimum hopping length of the compound.

4

Magnetic and electric behavior of NiFe2O4-PVDF nanocomposites

Sen S., Panda A. K., Prasad K.

Materials Science Poland

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2012

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Vol. 30, No. 4

419--425

EN

NiFe2O4-PVDF composites in different ratios (10 %, 30 % and 50 %) were prepared in two steps. Firstly, fine nanosized NiFe2O4 powder was synthesized using the precursor solution method. Then the composites were made by hot-press technique. The presence of both the phases (ceramic and polymer) was confirmed by XRD micrographs. The average particle size of the composites varied from 18-23 nm. SEM micrographs showed that the ferrite particles were embedded in the polymer matrix. The saturation magnetization and the remanence showed an increasing trend with the increase in ferrite content while the coercivity remained almost constant. Impedance plot showed the presence of a single semicircle, which indicates the presence of bulk effect. The composites exhibited non-Debye relaxation. The bulk conductivity followed the Arrhenius type of behavior. The conduction mechanism was explained by the Vervey-de-Boer mechanism.

5

Electrical conduction in Ba(Bi0.5Nb0.5)O3 ceramics. Impedance spectroscopy analysis

Prasad K., Bhagat S., Amarnath K., Choudhary S. N., Yadav K. L.

Materials Science Poland

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2010

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Vol. 28, No. 1

317--325

EN

A new lead free perovskite ceramics Ba(Bi0.5Nb0.5)O3 was fabricated by a conventional ceramic technique at 1185 °C and subsequent sintering at 1200 °C in air atmosphere. The XRD analysis of Ba(Bi0.5Nb0.5)O3 powder indicated the formation of a single-phase monoclinic structure. The ac conductivity data were found to obey the power law and showed a negative temperature coefficient for the resistance behaviour. The ac conductivity values were used to evaluate the density of states at the Fermi level, minimum hopping length and activation energy of the compound. The correlated barrier hopping model was found to successfully explain the mechanism of charge transport in Ba(Bi0.5Nb0.5)O3.

6

A novel technique for the synthesis of CaCu3Ti4O12 ceramics

Sen S., Sahu P., Prasad K.

Materials Science Poland

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2010

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Vol. 28, No. 1

265--271

EN

A novel, low temperature synthesis technique is developed for fabrication of nanocrystalline CaCu3Ti4O12 ceramic powders, using inexpensive and easily available reagents. Structural and microstructural characterization was undertaken by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The confirmation regarding the phase formation was done using the Reitveld analysis. The compound belongs to the cubic system with the lattice parameter a = 7.3985 A, which agrees well with the values reported in the literature. The particles formed were spherical in shape, with the average size of 70 nm.

7

Dielectric relaxation and ac conductivity of WO3 added (Na1/2Bi1/2)TiO3 ceramic

Prasad K., Kumari K., Chandra K. P., Yadav K. L., Sen S.

Materials Science Poland

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2009

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Vol. 27, No. 2

373--384

EN

Ceramic samples of WO3 added (Na1/2Bi1/2)TiO3 were prepared using a high-temperature solid-state reaction method. X-ray diffraction analyses indicate the formation of a single-phase orthorhombic structure. The apparent particle size and lattice strain are estimated using the Williamson-Hall plot. Dielectric studies revealed the relaxor behaviour and addition of WO3 shifted phase transition temperature as well as depolarization temperature of (Na1/2Bi1/2)TiO3 to higher side. ac impedance plots were used to analyse the electrical behaviour of samples in function of frequency at various temperatures. The ac impedance studies revealed the presence of the grain boundary effect and evidence of a negative temperature coefficient of resistance. Cole-Cole analysis indicated a non-Debye type dielectric relaxation. The ac conductivity obeys the universal power law. The pair approximation type correlated barrier hopping model explains the universal behaviour of the s exponent. The apparent activation energy of the conduction process and density of states at the Fermi level have been discussed.

8

Electrical properties of 0.90Pb[(Mg,Zn)1/3Ta2/3]O3-0.10PbTiO3 relaxor

Prasad S., Prasad K., Choudhary S.N., Sinha T.P.

Materials Science Poland

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2008

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Vol. 26, No. 3

475--485

EN

Polycrystalline 0.90Pb[(Mg2/3Zn1/3)1/3Ta2/3] O3-0.10PbTiO3 having a tetragonal perovskite type structure was prepared by the high temperature solid-state reaction method. Dielectric studies showed the relaxor behaviour with diffuse phase transition. High value of ∈max > 10000 was realized with the temperature of the permittivity maximum (Tm) around room temperature at 1 kHz. The frequency dependence of Tm has been modeled using Vogel-Fulcher relation. The dielectric relaxation in the present system was found analogous to the magnetic relaxation in spin-glass system. The shape of the complex impedance curve indicated that the system exhibited almost Debye type dielectric relaxation at 350 °C, where as non-Debye character was observed at temperatures ≥ 325 °C. Further the relaxation frequency was found to shift towards higher frequencies with an increase in temperature.

9

Determination of selenium(IV) after co-precipitation with Fe-Ti layered double hydroxides

Prasad K., Rao K. S., Gladis J. M., Naidu G. R. K., Rao T.P.

Chemia Analityczna

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2006

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Vol. 51, No. 4

613-622

EN

The narrow margin between beneficial and toxic properties of selenium requires precise analytical methods for its fast and reliable determination. We have developed a precise co-precipitative preconcentration and separation procedure for SeO2-3 in the pH range 4.0-6.0 using Fe-Ti layered double hydroxides prepared from synthetic solutions of Fe(III) and Ti(IV), and industrial effluent. The obtained layered double hydroxide co-precipitant with SeO2-3 was dissolved in 2 mol L-1 H2SO4 and concentration of selenium was determined spectrophotornetrically. Calibration plot was linear over the concentration range of selenium (IV) 1-100 &mi;g L-1. Detection limit (S/N = 3) for selenium(IV) was 1.0 &mi;g L-1. Relative standard deviation for 5 μg L-1 of the analyte was 3.0% (n= 5). The accuracy of the developed method was tested by analyzing certified reference materials of marine sediment (MESS-3) and soil (IAEA-Soil 7). Furthermore, the developed procedure has been success fully applied to the analysis of selenium(lV) in soil and river and marine sediment samples.

PL

Stosunkowo niewielka różnica między pożytecznymi i szkodliwymi dla zdrowia człowieka stężeniami selenu stwarza potrzebę szybkich i wiarygodnych metod oznaczania tego pierwiastka. Opracowano szybką i precyzyjną metodę zatężania i oddzielania SeO2-3 z roztworów o pH 4-6. W metodzie zastosowano warstwowo ułożone wodorotlenki Fe-Ti otrzymane z syntetycznych roztworów Fe(III) i Ti(IV) oraz z przemysłowych odcieków.Współstrącony na podwójnej warstwie wodorotlenków SeO2-3 rozpuszczano w 2 mol L-1 roztworze H2SO4 a zawartość selenu oznaczano spectrofotometrycznie. Krzywa kalibrowania była prostoliniowa w zakresie stężenia Se(IV) 1-100&mi;g L-1. Granicę wykrywalności (sygnał: szum=3) oszacowano na 1.0-100. Względne odchylenie standardowe pomiarów (5 &mi;g L-1, n = 5) wynosiło 3%. Dokładność metody testowano analizując materiały wzorcowe osadów morskich (MESS-3) i gleby (IAEA-Soil 7). Wykonano analizy zawartości selenu(IV)w próbkach osadów rzecznych i morskich oraz w glebie.