Studies of Structural, Microstructure, Dielectric and Optical Properties of Bismuth-Based Complex Perovskite Modified Bismuth Ferrite: BiFeO3 –(Bi0.5 Na0.25 K0.25 )(Ti0.5 Mn0.5 )O3 Ceramics

S. K. Sourav,S. K. Parida,R. N. P. Choudhary,Umakant Prasad 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.5

This communication describes a solid-state reaction prepared bismuth oxide and related complex compounds (BNKMT) of a chemical composition (1-x)BiFeO3-x(Bi0.5 Na0.25 K0.25 Ti0.5 Mn0.5 O3), where x = 0.15 and 0.20. Structural studies of the complex system show rhombohedral crystal symmetry (#R3c). The homogeneous distribution of the grains and grain boundaries throughout the sample surface clearly defined grain boundaries, which play a significant part in the conductivity mechanism, as revealed by the analysis of scanning electron microscopy micrographs and electrical properties. An energydispersive X-ray analysis spectrum was used to verify the processed materials’ purity and composition. According to the analysis of the FTIR-ATR spectrum, the prepared samples show stretching bands that correspond to their constituent elements. A dielectric investigation confirmed that the Maxwell–Wanger type of dielectric dispersion is present in the samples. Studies of impedance parameters as a function of temperature and frequency result in a negative temperature coefficient of resistance behavior. While ac conductivity research supports the presence of a thermally activated relaxation process in the materials. Analysis of electric modulus discloses a non-Debye type relaxation mechanism in the studied sample. Because the samples are semiconducting at high temperatures, semi-circular arcs have been seen in both the Nyquist and Cole–Cole plots. When compared to BNKTM 15%, BNKTM 20% has a bandgap energy of 5.9 eV, according to the analysis of UV visible spectra.

Experimental investigation of Wheeler's hardening model for Pusan clays

Chung, S.G.,M. Suneel,K.N. Prasad,Rao, K.G. 東亞大學校建設技術硏究所 2004 硏究論文集 Vol.28 No.1

The present paper adopts Wheeler's model (1997) to evaluate its application to Pusan clays. A program of triaxial and consolidation tests on samples of Pusan clays at Yangsan, Korea was under taken to investigate the applicability of the model adopted. The model parameters are evaluated by describing the initial state of the soil. Model predictions are shown to be qualitatively consistent with experimental observations, but refinement seems to be required to have much better agreement between experimental results and model predictions.

Forging of cast Mg-3Sn-2Ca-0.4Al-0.4Si magnesium alloy using processing map

K. P. Rao,K. Suresh,Y. V. R. K. Prasad,N. Hort,K. U. Kainer 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

Mg-3Sn-2Ca (TX32) alloy has good creep resistance but limited workability. Minor amounts of Al and Si have been added to TX32 for improving its hot workability. The processing map for the TX32-0.4Al-0.4Si alloy exhibited two workability domains in the temperature and strain rate ranges: (1) 310-415°C/0.0003-0.003 s -1 and (2) 430-500°C/0.003-3 s -1 . The alloy exhibited flow instability at temperatures < 350°C at strain rates > 0.01 s -1 . The alloy has been forged to produce a cup shape component to validate these findings of processing map. Finite-element (FE) simulation has been performed for obtaining the local variations of strain and strain rate within the forging. The microstructures of the forged components under the optimal domain conditions revealed dynamically recrystallized grains, and those forged in the flow instability regime have fractured and exhibited flow localization bands and cracks. The experimental loadstroke curves correlated well with those obtained by FE simulation.

Trihalomethanes in the Cooling Discharge of a Power Plant on Chlorination of Intake Seawater

R. K. Padhi,S. Subramanian,A. K. Mohanty,S. N. Bramha,M. V. R. Prasad,K. K. Satpathy 대한환경공학회 2012 Environmental Engineering Research Vol.17 No.-

Trihalomethanes (THMs) formation and species distribution in the discharged chlorinated cooling seawater of a nuclear power plant was assessed during Aug 2010 to July 2011. The monthly variation of chlorine demand of the source seawater under laboratory chlorination conditions was studied for the same period. The entire period can be divided into two separate zones; viz. Feb, Mar, Apr, Sep, Oct (low chlorine demand), and May, Jun, Jul, Aug, Nov, Dec, Jan (high chlorine demand) months. Bromoform was found to be the single dominant THMs species in the chlorinated cooling seawater discharge. The THMs concentration was observed to be highest for the month of Nov 2010 (41 μg/L), and lowest for Feb 2011(12 μg/L). Under laboratory chlorination of intake seawater with 1 ppm Cl2, the concentration of THMs that was formed within 5–15 min is in agreement with the actual concentration in the discharge water. A simplified predictive approach is proposed for the total THMs concentration at the cooling discharge outlet of a power plant, based on the actual chlorine demand of source water.

Enhancing Performance of Dual-Gate FinFET with High-K Gate Dielectric Materials in 5 nm Technology: A Simulation Study

M. V. Ganeswara Rao,N. Ramanjaneyulu,Balamurali Pydi,Umamaheshwar Soma,K. Rajesh Babu,Satti Harichandra Prasad 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.6

The rapid advancement in nanoscale devices demands innovative gate dielectric materials to replace traditional Silicon dioxide. This paper investigates the electrical behavior and performance of a dual-gate FinFET employing different high-K gate dielectric materials (Silicon dioxide, Hafnium oxide, Titanium oxide) through ATLAS 2D simulation in 5 nm technology. We analyze how these high-K gate dielectric materials influence the device, focusing on performance enhancement. The study highlights various key performance parameters (ION, IOFF, gm, gds, RON, TF, EV, V IL, V IH, NML, NMH) and reveals a significant performance improvement with HfO2 dielectric material in the proposed Dual-Gate FinFET. Achieving impressive performance parameters ( ION : 21.59 mA, IOFF : 21 µA, Maximum net Electric field: 1221290 V/cm, g m(max) : 0.05187 S, gds(max) : 0.03462 S, RON(max) : 25.93 kΩ , TFmax: 5.02, G ainmax : 90.233, EVmax : 67.532 V, V IL : 0.21 V, V IH : 0.4 V, NML : 198 V, NMH : 600 V), this paper provides valuable insights for designing high-performance devices with HfO2 dielectric material.

Structural, FTIR and ac conductivity studies of NaMeO₃ (Me ≡ Nb, Ta) ceramics

Roy, Sumit K.,Singh, S.N.,Kumar, K.,Prasad, K. Techno-Press 2013 Advances in materials research Vol.2 No.3

Lead-free complex perovskite ceramics $NaMeO_3$ ($Me{\equiv}Nb$, Ta) were synthesized using conventional solid state reaction technique and characterized by structural, FTIR and electrical (dielectric and ac conductivity) studies. The crystal symmetry, space group and unit cell dimensions were determined from the experimental results using FullProf software. XRD analysis of the compound indicated the formation of single-phase orthorhombic structure with the space group Pmmm (47). Dielectric studies showed the diffuse phase transition at $394^{\circ}C$ for $NaNbO_3$ and $430^{\circ}C$ for $NaTaO_3$. Ac conductivity in both the compounds follows Jonscher's power law.

Cytokine expression pattern in milk somatic cells of subclinical mastitis-affected cattle analyzed by real time PCR

Bhatt, Vaibhav D.,Khade, Prasad S.,Tarate, Sagar B.,Tripathi, Ajai K.,Nauriyal, Dev S.,Rank, Dharamshi N.,Kunjadia, Anju P.,Joshi, Chaitanya G. The Korean Society of Veterinary Science 2012 大韓獸醫學會誌 Vol.52 No.4

The expression profiles of inflammatory cytokines viz. interleukins (IL)-6, IL-8, IL-12, granulocyte macrophage-colony stimulating factor, interferon-${\gamma}$ and tumor necrosis factor-${\alpha}$ in response to subclinical mastitis in indigenous cattle breed Kankrej (n = 6), Gir (Bos indicus) (n = 12) and crossbred (Bos taurus${\times}$Bos indicus) (n = 7) were investigated using quantitative real time PCR. Significant correlation (p < 0.05) was observed between total bacterial load and somatic cell count (SCC) in all three breeds of cattle. All the cytokines were observed to be up-regulated compared to cows with healthy quarters, however, level of their expression varied among three breeds of cattle. In Kankrej most cytokines were found to be transcribed to higher levels than in other two breeds; the milk had higher load of bacteria but not so high SCC, implying that Kankrej has a higher inherent resistance against mastitis. The results of present study indicated that mammary glands of crossbred cattle are more sensitive to bacterial infection than indigenous breed of cattle as they elicit immune response at lower bacterial load and result into higher SCC. Research on identification of factors responsible for differentially expressed cytokines profiles and use of cytokines as immunomodulatory tools can pave way for formulating control strategies against bovine mastitis.

Laccase Production Using Pleurotus ostreatus 1804 Immobilized on PUFCubes in Batch and Packed Bed Reactors: Influence of Culture Conditions

K. Krishna Prasad,S. Venkata Mohan,Y. Vijaya Bhaskar,S. V. Ramanaiah,V. Lalit Babu,B. R. Pati,P. N. Sarma 한국미생물학회 2005 The journal of microbiology Vol.43 No.3

The feasibility of laccase production by immobilization of Pleurotus ostreatus 1804 on polyurethane foam (PUF) cubes with respect to media composition was studied in both batch and reactor systems. Enhanced laccase yield was evidenced due to immobilization. A relatively high maximum laccase activity of 312.6 U was observed with immobilized mycelia in shake flasks compared to the maximum laccase activity of free mycelia (272.2 U). It is evident from this study that the culture conditions studied, i.e. biomass level, pH, substrate concentration, yeast extract concentration, Cu2+ concentration, and alcohol nature, showed significant influence on the laccase yield. Gel electrophoretic analysis showed the molecular weight of the laccase produced by immobilized P. ostreatus to be 66 kDa. The laccase yield was significantly higher and more rapid in the packed bed reactor than in the shake flask experiments. A maximum laccase yield of 392.9 U was observed within 144 h of the fermentation period with complete glucose depletion.

Microwave synthesis, characterization and in-vitro evaluation of nanostructured biphasic calcium phosphates

N. Rameshbabu,K. Prasad Rao 한국물리학회 2009 Current Applied Physics Vol.9 No.11

Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) represent the main types of calcium phosphates used for bone and dental surgery. HA is thermodynamically the most stable phase in physiological conditions and has the ability for direct chemical bonding to bone while β-TCP is found to be resorbable invivo with new bone growth replacing the implanted β-TCP. The bioactivity and bioresorbability of the biphasic calcium phosphate (BCP) ceramics can be controlled by varying HA/β-TCP ratio. Nanostructured calcium phosphates promote osseointegration, which is critical for the clinical success of orthopedic/dental implants. The present study demonstrates the preparation of nanostructured BCP ceramics by microwave processing. Since the physiological stability is, important parameter while selecting the material for implantation, the in-vitro dissolution studies of BCPs with different HA/β-TCP ratios were carried out under the conditions of osteoclastic resorption. The results suggest the dissolution of the BCP ceramics can be fine-tuned by varying the HA/β-TCP ratios. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) represent the main types of calcium phosphates used for bone and dental surgery. HA is thermodynamically the most stable phase in physiological conditions and has the ability for direct chemical bonding to bone while β-TCP is found to be resorbable invivo with new bone growth replacing the implanted β-TCP. The bioactivity and bioresorbability of the biphasic calcium phosphate (BCP) ceramics can be controlled by varying HA/β-TCP ratio. Nanostructured calcium phosphates promote osseointegration, which is critical for the clinical success of orthopedic/dental implants. The present study demonstrates the preparation of nanostructured BCP ceramics by microwave processing. Since the physiological stability is, important parameter while selecting the material for implantation, the in-vitro dissolution studies of BCPs with different HA/β-TCP ratios were carried out under the conditions of osteoclastic resorption. The results suggest the dissolution of the BCP ceramics can be fine-tuned by varying the HA/β-TCP ratios.

Effect of Piper betle Leaf Extract on Alcoholic Toxicity in the Rat Brain

K.V. Pugalendi,R. Saravanan,N. Rajendra Prasad 한국식품영양과학회 2003 Journal of medicinal food Vol.6 No.3

The protective effect of Piper betle, a commonly used masticatory, has been examined in the brain of ethanol-administered Wistar rats. Brain of ethanol-treated rats exhibited increased levels of lipids, lipid peroxidation, and disturbancesin antioxidant defense. Subsequent to the experimental induction of toxicity (i.e., the initial period of 30 days), aqueous P.betleextract was simultaneously administered in three different doses (100, 200, and 300 mg kg2 1) for 30 days along withthe daily dose of alcohol. P. betlecoadministration resulted in significant reduction of lipid levels (free fatty acids, choles-terol, and phospholipids) and lipid peroxidation markers such as thiobarbituric acid reactive substances and hydroperoxides.Further, antioxidants, like reduced glutathione, vitamin C, vitamin E, superoxide dismutase, catalase, and glutathione perox-idase, were increased in P. betle-coadministered rats. The higher dose of extract (30 mg kg 2 1) was more effective, and theseresults indicate the neuroprotective effect of P. betlein ethanol-treated rats.