sushma kumari
@iitp.ac.in
Scopus Publications
Scopus Publications
Sushma Kumari and Sujoy Kumar Samanta
Walter de Gruyter GmbH
Abstract The two-dimensional cylindrically shaped multiphase meat sample was modelled for microwave processing for two different interaction techniques i.e., lateral and radial during mono-mode operation of waveguide. The study was aimed to analyze the effect of volume fraction and sample size along with the duration of the procedure on the heat distribution corresponding to specified frequency and intensity of microwave. Procedure exhibiting higher heating rate and lower thermal non-homogeneity was set as the deciding factor for an optimal heating scheme. In order to achieve optimal processing at both 915 and 2450 MHz frequency, rotation of smaller samples and non-rotation of larger samples were recommended in most of the case studies; however, few exceptions were also observed and reported. In addition, reciprocity between volume fraction, intensity of the microwave radiation and procedure duration was also discussed. Overall, the present study would guide the studies on the microwave processing of two-dimensional multiphase meat.
Sushma Kumari and Sujoy Kumar Samanta
Elsevier BV
Sushma Kumari and Sujoy Kumar Samanta
Institute of Electrical and Electronics Engineers (IEEE)
This investigation involves the study of electrical properties, i.e., conductivity and permittivity of human whole blood and its different components with/without various additives at different temperatures. The open-ended coaxial probe measurement technique was employed to perform the study for the frequency range of 0.3–6.5 GHz. The dielectric behaviors of the freshly received whole blood from five different donors with different anticoagulants and clotting gel were studied at temperatures ranging from 5 °C to 45 °C. The differences in the dielectric behaviors of the whole blood, its different components [packed red blood cells (RBCs), plasma, and serum], and RBC suspensions were also analyzed. The plain whole blood and the whole blood samples incorporated with the clotting gel exhibited lower dielectric behaviors compared to those with the whole blood samples incorporated with the anticoagulants. The analysis of the whole blood, its different components, and RBC suspensions inferred that the packed RBCs exhibited the lowest dielectric constant, loss, and conductivity, and these values were increased for the whole blood followed by serum, plasma, and RBC suspensions, respectively. The dielectric behaviors of the whole blood and its components were observed to be significantly affected by the presence of different additives and also due to the variation in frequencies and temperatures. The modified Debye relaxation model included with the static conductivity term was fitted to the measured permittivity. The dielectric responses of biological samples are very useful and paramount for understanding the specific absorption rate (SAR) and other thermal and nonthermal effects of the radiation.
Sandhya Mishra, Sushma Kumari, Prashant Kumar, and Sujoy Kumar Samanta
Elsevier BV
Sushma Kumari, Sujoy Kumar Samanta, and Brij Saxena
Universitat Politècnica de València
Economical and efficient warming of pre-transfusion human blood has been a subject of extensive investigation. The objective of this study is to identify and analyze the effect of enhanced microwave warming of bank blood. The sample here has been assumed to be a 2D cylinder interacting with microwave irradiation. The mathematical interpretation for the study is performed by solving the equation of electromagnetic wave propagation along with the equation of energy balance and pertinent boundary conditions. The samples after being subjected to both lateral and radial irradiations of same intensity are investigated for the power absorption in the sample with respect to the sample size. The preliminary observations obtained are further analyzed and extended for spatial distribution scrutiny. The collaborative analysis of the spatial distributions of temperature and power in the human blood along with high heating rate and low thermal non-uniformity determine the optimal heating strategy. The observations at different sample sizes recommend radial irradiation as the optimal heating strategy for samples corresponding to OP: 1 and 3, and lateral irradiation for samples corresponding to OP: 2, respectively. Considering all the aspects, the present work recommends an efficient way for enhanced microwave assisted heating of body fluid samples (2D cylindrical geometry) with known or measurable dielectric properties.
Sushma Kumari, Sujoy Kumar Samanta, and Kush Patel
Universitat Politècnica de València
The exigencies of a swift, qualitative and economical procedure for the food industry was addressed by the microwave assisted processing such as heating, drying, thawing, etc1. A food material in itself is a complex sample with multiple components and varying dielectric properties which makes its mathematical modeling arduous. The most realistic approach is to consider the food as a porous dielectric which basically consists of a continuous phase and one or more dispersed phases2. The porous dielectrics considered for this study is meat as the continuous phase and oil, water or air as dispersed phase. A theoretical analysis has been performed to study the thermal effects on the 2D cylindrical porous food dielectrics subjected to microwave irradiation. The analysis comprises of different porosity conditions (Φ = 0.1, 0.25 and 0.4), different initial intensities (I0 = 1 and 1.5 Wcm-2) and different dispersed phases. Galerkin finite element analysis has been used to solve electric field and energy balance equations with suitable boundary conditions.