Existence of Partially Degenerate Electrical Transport in Intermetallic Cu2SnSe3 Thermoelectric System Sintered at Different Temperatures

K. Gurukrishna,H. R. Nikhita,S. M. Mallikarjuna Swamy,Ashok Rao 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

A detailed investigation on the temperature dependent electrical properties of Cu2SnSe3system, synthesized via conventionalsolid-state reaction at different sintering temperatures are presented in this communication. All the samples exhibit degeneratesemiconducting nature at low temperatures. The existence of small polarons and hence electron–phonon interactionsare confirmed at temperatures below 400 K. A transition was observed from degenerate to non-degenerate semiconductingbehaviour at high temperatures (T > 400 K). The study confirms the unusual transition in electrical resistivity as well asthermopower at high temperatures in all the compounds, demonstrating the existence of minority carrier excitation alongwith temperature-triggered ionisation of the defects. The transport behaviour is further supported by an upward movementof Fermi level away from the valence band. Highest weighted mobility of 8.2 cm2V−1 s−1 at 673 K was obtained for thesample sintered at 1073 K. A considerable decrease in electrical resistivity with increase in temperature (T > 400 K) hasdriven the power factor to increase exponentially, thereby achieving highest value of 188 μV/mK2 (at 673 K) for the samplesintered at 673 K.

Non-linear free vibrations and post-buckling analysis of shear flexible functionally graded beams

K. Sanjay Anandrao,R.K. Gupta,P. Ramchandran,G. Venkateswara Rao 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.44 No.3

Large amplitude free vibration and thermal post-buckling of shear flexible Functionally Graded Material (FGM) beams is studied using finite element formulation based on first order Timoshenko beam theory. Classical boundary conditions are considered. The ends are assumed to be axially immovable. The von-Karman type strain-displacement relations are used to account for geometric non-linearity. For all the boundary conditions considered, hardening type of non-linearity is observed. For large amplitude vibration of FGM beams, a comprehensive study has been carried out with various lengths to height ratios, maximum lateral amplitude to radius of gyration ratios, volume fraction exponents and boundary conditions. It is observed that, for FGM beams, the non-linear frequencies are dependent on the sign of the vibration amplitudes. For thermal post-buckling of FGM beams, the effect of shear flexibility on the structural response is discussed in detail for different volume fraction exponents, length to height ratios and boundary conditions. The effect of shear flexibility is observed to be predominant for clamped beam as compared to simply supported beam.

Laccase- and Peroxidase-Free Tyrosinase Production by Isolated Microbial Strain

( Sambasiva Rao K. R. S. ),( N. K. Tripathy ),( Y. Mahalaxmi ),( R. S. Prakasham ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.2

Laccase- and peroxidase-free tyrosinase has commercial importance in the production of L-3, 4-dihydroxyphenylalanine (L-DOPA), which is mainly used in the treatment of Parkinson`s disease. In the present study, isolation of an actinomycetes microbial strain capable of producing only tyrosinase is reported. Among all soil isolates, three individual colonies revealed black color around the colony in the presence of tyrosine. Further screening for laccase and peroxidase activities using syringaldazine denoted that one of the isolates, designated as RSP-T1, is laccase and peroxidase negative and produces only tyrosinase. The microbe was authenticated as Streptomyces antibioticus based on 16S ribotyping. Effective growth of this isolate was noticed with the use of medium (pH 5.5) containing casein acid hydrolysate (10.0 g/l), K2HPO4 (5.0 g/l), MgSO4 (0.25 g/l), L-tyrosine (1.0 g/l), and agar (15 g/l). The scanning electron micrograph depicted that the microbe is highly branched and filamentous in nature. The enzyme production was positively regulated in the presence of copper sulfate. The impact of different fermentation parameters on tyrosinase production depicted that the maximized enzyme titer values were observed when this isolate was grown at 6.5 pH and at 30oC temperature under agitated conditions (220 rpm). Among all the studied physiological parameters, agitation played a significant role on tyrosinase production. Upon optimization of the parameters, the yield of tyrosinase was improved more than 100% compared with the initial yield.

Cracking in reinforced concrete flexural members - A reliability model

Rao, K. Balaji,Rao, T.V.S.R. Appa Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.7 No.3

Cracking of reinforced concrete flexural members is a highly random phenomenon. In this paper reliability models are presented to determine the probabilities of failure of flexural members against the limit states of first crack and maximum crackwidth. The models proposed take into account the mechanism of cracking. Based on the reliability models discussed, Eqs. (8) and (9) useful in the reliability-based design of flexural members are presented.

Design, Synthesis and Biological Evaluation of Novel Analogs of Bortezomib

Rao, R. Janaki Rama,Rao, A.K.S. Bhujanga,Swapna, K.,Rani, B. Baby,Kumar, S. Prasanna,Awantika, S.,Murthy, Y.L.N. Korean Chemical Society 2011 대한화학회지 Vol.55 No.5

Novel analogs of bortezomib were designed, synthesized and in vitro biological evaluation was carried out using human tumor cell lines A549 and PC3. Docking studies of these analogs of bortezomib was discussed. According to biological investigations, the inhibitors 4, 6, and 8 were found to be more potent than reference drug candidate bortezomib. A549 cell line showed significant sensitivity towards 4, 6, and 8 with $IC_{50}$ values 14.03, 18.5, and 12.4 nM, respectively, and PC3 cell line showed IC50 values 26.1, 37.0, and 21.2 nM, respectively. The $IC_{50}$ values of bortezomib in these cell lines are 27.3 nM and 42.0 nM.

Modelling of strains in reinforced concrete flexural members using alpha-stable distribution

K. Balaji Rao,M. B. Anoop,K. Kesavan,S. R. Balasubramanian,K. Ravisankar,Nagesh R. Iyer 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.5

Large fluctuations in surface strain at the level of steel are expected in reinforced concrete flexural members at a given stage of loading due to the emergent structure (emergence of new crack patterns). This has been identified in developing deterministic constitutive models for finite element applications in Ibrahimbegovic et al. (2010). The aim of this paper is to identify a suitable probability distribution for describing the large deviations at far from equilibrium points due to emergent structures, based on phenomenological, thermodynamic and statistical considerations. Motivated by the investigations reported by Prigogine (1978) and Rubi (2008), distributions with heavy tails (namely, alpha-stable distributions) are proposed for modeling the variations in strain in reinforced concrete flexural members to account for the large fluctuations. The applicability of alpha-stable distributions at or in the neighborhood of far from equilibrium points is examined based on the results obtained from carefully planned experimental investigations, on seven reinforced concrete flexural members. It is found that alpha-stable distribution performs better than normal distribution for modeling the observed surface strains in reinforced concrete flexural members at these points.

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.

Line${\times}$Tester Analysis of Certain Quantitative Traits in Silkworm Bombyx mori L. under Optimum and Stress Rearing Conditions

Rao, P.Sudhakara,Datta, R.K.,Kumari, K.M.Vijaya,Palit, A.K.,Bhat, S.A. Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.8 No.1

The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

EXISTENCE AND UNIQUENESS OF SUZUKI TYPE RESULT IN S_b-METRIC SPACES WITH APPLICATION TO INTEGRAL EQUATIONS

K.P.R. Rao,W. Shatanawi,G. N. V. Kishore,Kamaleldin Abodayeh,D. Ram Prasad 경남대학교 기초과학연구소 2018 Nonlinear Functional Analysis and Applications Vol.23 No.2

In this paper we prove a Suzuki type unique common coupled fixed point theorem for two pairs of w-compatible mappings along with (ψ - φ) - and Rational contraction conditions in S_b-metric spaces. We also furnish an example as well as application to integral equation.

Heterotic Expression in Silk Productivity of Newly Evolved Thermo-tolerant Bivoltine Hybrids of Silkworm Bombyx mori L.

Rao, P.Sudhakara,Datta, R.K.,Vijaya Kumari, K.M.,Palit, A.K.,Haque Rufaie, S.Z. Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.9 No.1

Studies on heterotic expression in the silk productivity of 66 thermo-tolerant bivoltine hybrids reared under high temperature $(36{\times}1^{\circ}C)$ and low humidity (60${\times}$5%) conditions revealed that manifestation of heterosis was highly significant for majority of the quantitative traits contributing to more cocoon productivity. Observations were made on 8 economically important traits such as fecundity, pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon filament length and raw silk. Analysis of variance results revealed great deal of variability indicating significant (P < 0.001) variations. Out of 66 hybrids, 7 hybrids exhibited positive heterosis for seven traits and 4 hybrids expressed significant hetero-beltiosis for 6 traits, out of 8 traits evaluated. Based on results, the hybrids ${SR_1} {\times} {SR_5}and {CSR_2} {\times} {SR_5}$ are adjudged as most promising ones and can be exploited commercially in tropical climates to increase the cocoon productivity.