Synthesis, magnetic and Mossbauer spectroscopic studies of Cr doped lithium ferrite nanoparticles

Srivastava, M.,Layek, S.,Singh, J.,Das, A.K.,Verma, H.C.,Ojha, A.K.,Kim, N.H.,Lee, J.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.591 No.-

Lithium-based ferrites are promising and potential magnetic materials for microwave applications. They possess a spinel (AB<SUB>2</SUB>O<SUB>4</SUB>) type crystal structure, where the distributions of metal cations over the tetrahedral (A) and octahedral (B) voids play a crucial role for exhibiting different physical properties. Among various parameter of synthesis, pH is an important factor that influences the cation distribution over A and B voids, overall growth of the nanoparticles and different physical properties. In the present work single phase Cr substituted lithium ferrite nanoparticles have been synthesized by the sol-gel method at different pH. The phase identification and crystallite size have been probed by X-ray diffraction studies. The crystallite size changes by 44.2-48.8nm upon varying the pH from 3.5 to 11.5. In order to investigate the cations distribution at A/B sites, Mossbauer spectroscopic measurements were done. The values of magnetic hyperfine field obtained from the Mossbauer data for the A and B sites are ~49.5T and 51T, respectively. Moreover, it is observed that the area ratio of B site to A site increases with increasing the pH. This observation further suggests that the B site is more preferable for Fe<SUP>3+</SUP> cations at higher pH than the A site. The magnetic parameter such as saturation magnetization (M<SUB>s</SUB>), remanent magnetization (M<SUB>r</SUB>), coercive field (H<SUB>C</SUB>) and squareness (S) are determined by vibrating sample magnetometer (VSM) measurements, which show a consistent increase with increasing pH. The reason for the variation in magnetic properties has been explained on the basis of increased Fe<SUP>3+</SUP> cation occupancies at the B site and size effect, which is well supported by Mossbauer spectroscopic and XRD studies.

Effect of incorporation of soy protein isolate and inulin on quality characteristics and shelf-life of low–fat duck meat sausages

Moirangthem S.,Laskar S. K.,Das A.,Upadhyay S.,Hazarika R. A.,Mahanta J. D.,Sangtam H. M. 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: Low fat duck meat sausages were prepared by replacing the fat in the formulations with soy protein isolate (SPI) and inulin to find the best formulation having superior shelflife without affecting its quality attributes. Methods: Four sausage mix formulations were prepared viz.control (0% SPI and inulin), T1 (2.5% inulin), T2 (2.5% SPI), and T3 (2.5% SPI+2.5% inulin) replacing duck fat as per the recipe. Five batches of duck meat sausages of each formulation were prepared, and the final products were evaluated for physico-chemical, organoleptic, and microbiological qualities. Results: The % moisture and crude protein content of the sausages revealed an increasing trend (p<0.01) from control to the treated formulations, while the % total ash contents were found to be non-significant (p>0.05). On the contrary, the per cent ether extract decreased significantly (p<0.01) from the control to the treated groups. In terms of calorie value, control samples exhibited the highest values with a significant (p<0.01) regression from control to treated formulation, respectively. The colour profile study (L, a*, b*) of the formulations were found to be non-significant. Texture profile study in terms of springiness, cohesiveness, chewiness, and resilience revealed no significant difference in all the treatment groups except the hardness scores, which revealed a significantly (p<0.01) increasing trend from control to the treated formulations. The total viable count showed a significant decrease in the treated groups. However, there was a significant increase in the bacterial load during the storage till day 15th. The total viable psychrophilic bacterial count showed a significant (p<0.01) increase in bacterial load from day 5th to 15th day of storage. Colititre counts were negative for all the formulations until the 15th day of storage. Conclusion: The present study results may conclude that duck meat sausages could be prepared satisfactorily by replacing duck fat with SPI and inulin at the rate of 2.5% of each with superior quality attributes. Objective: Low fat duck meat sausages were prepared by replacing the fat in the formulations with soy protein isolate (SPI) and inulin to find the best formulation having superior shelflife without affecting its quality attributes.Methods: Four sausage mix formulations were prepared viz.control (0% SPI and inulin), T₁ (2.5% inulin), T₂ (2.5% SPI), and T₃ (2.5% SPI+2.5% inulin) replacing duck fat as per the recipe. Five batches of duck meat sausages of each formulation were prepared, and the final products were evaluated for physico-chemical, organoleptic, and microbiological qualities.Results: The % moisture and crude protein content of the sausages revealed an increasing trend (p<0.01) from control to the treated formulations, while the % total ash contents were found to be non-significant (p>0.05). On the contrary, the per cent ether extract decreased significantly (p<0.01) from the control to the treated groups. In terms of calorie value, control samples exhibited the highest values with a significant (p<0.01) regression from control to treated formulation, respectively. The colour profile study (<i>L</i>, <i>a</i>*, <i>b</i>*) of the formulations were found to be non-significant. Texture profile study in terms of springiness, cohesiveness, chewiness, and resilience revealed no significant difference in all the treatment groups except the hardness scores, which revealed a significantly (p<0.01) increasing trend from control to the treated formulations. The total viable count showed a significant decrease in the treated groups. However, there was a significant increase in the bacterial load during the storage till day 15th. The total viable psychrophilic bacterial count showed a significant (p<0.01) increase in bacterial load from day 5th to 15th day of storage. Colititre counts were negative for all the formulations until the 15th day of storage.Conclusion: The present study results may conclude that duck meat sausages could be prepared satisfactorily by replacing duck fat with SPI and inulin at the rate of 2.5% of each with superior quality attributes.

Interface of Korean Culture and the Contours of Sacred-space

Das,A. K. 한국박물관학회 2008 博物館學報 Vol.- No.14·15

In the year 2006 the UNESCO conducted a world-wide survey particularly in areas known for the traditional way of life specifically in the Asia-Pacific region to collect data on the dying traditions. The data bank on this aspect would reveal a large body of traditions in Asia both tangible and intangible are either dying or struggling for survival. In India. China. Korea and the countries of South-east Asia many a form of arts and crafts. traditions. customs. rites . rituals. songs . dances. performances. ceremonies. languages and dialects so on and so forth are fast on the wane. The change is inevitable in terms of social. cultural and economic development. It is part and parcel of human life and history. Yet certain value and finer sides of life needs continuity to sustain cultural identity. In this context the relevance of the heritage conservation has been accepted world over. The stipulations of the UNESCO Conventions on the Safeguard of Tangible and the Intangible Human Heritage' (2003) are a matter of great concern to the modern and traditional societies. ll In this context it may be mentioned that the tangible heritages have been well looked after in highly industrialized countries like Korea and Japan in East Asia. However. preservation of intangible heritage here needs some attention. National cultural identity inherent in ways of human life is represented by the tangible and the intangible elements that are subjected to change. However. the significance of the intangible heritage lies in the fact that it carry forward past to the present in a dynamic form.

$\alpha$- and $\beta$-Amylase Isozyme Expresser Native Proteins in Tropical Silkworm Bombyx mori L.

Chattopadhyay, G.K.,Verma, A.K.,Sengupta, A.K.,Das, S.K.,Urs, S.Raje Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.8 No.2

Amylase isozyme based three multivoltine viz., N+p, Np, N+ $p^{cho}$ and two bivoltine-D6+p, D6p syngenic lines (Syn. L) were developed from germplasm (GP) stocks Nistari (N) and D6 respectively. haemolymph isozyme pattern at pH 7.0 and 8.5 depicted a total 11 number (Am $y_{1 to 6}$ at pH 7.0 and Am $y^{l to 5}$ at pH 8.5) of native proteins (NP) of various sizes are amylase isozyme expressers. Among eleven NPs, two NPs of 770 kDa (Am $y^{6}$ at pH 7.0) and 376 kDa (Am $y^3$ at pH 8.5) are $\alpha$-amylase expressers and remaining NPs of 370, 364, 350, 329 and 274 kDa at pH 7.0 and 206, 292, 416, 725 kDa at pH 8.5 are $\beta$-amylase expressers. Accordingly, digestive juice amylase isozyme pattern at aforesaid pH also depicted a total number of 10 NPs (Am $y^{1 to 5}$) at each pH 7.0 and 8.5 are amylase expressers of which NP of 387 kDa (Am $y^4$ at pH 7.0) and 780 kDa (Am $y^{5}$ at pH 8.5) are a-amylase expresser. Remaining NPs of 338,297 & 216 kDa at pH 7.0 and 370, 341, 329 &302 kDa at pH 8.5 are $\beta$-amylase expresser. Recurrent backcross lines (RBL) viz., N+pRBL and NpRBL were developed through introgression of high shell weight character (a multigenic trait) to be used further for congenic line (Con. L) development and to understand any association with introgressed character. Isozyme pattern in haemolymph of RBLs depicted only one $\alpha$-amylase of 770 kDa at pH 7.0 and 376 kDa at pH 8.0 with three and four respective $\beta$-amylase bands but in bivoltine lines numbers of $\beta$-amylase bands vary between 1 to 2 at aforesaid pH. Variability was also observed in digestive juice of multivolitine and its RBLs but bivoltine lines express null activity at both pH except appearance of one very week $\alpha$-amylase band D6+p at pH 8.5. Overall study suggests that not a single NP at both pH is common for expression of any band of amylase isozyme i.e., a totally different set of proteins are the amylase isozyme expresser at specific pH and no molecular factor of amylase is associated in developed RBLs which showed improvement on survival, single cocoon shell weight (SCSW) and single filament length over receptor parents.s.s.s.

α- and β-Amylase Isozyme Expresser Native Proteins in Tropical Silkworm Bombyx mori L.

( G. K. Chattopadhyay ),( A. K. Verma ),( A. K. Sengupta ),( S. K. Das ),( S. Raje Urs ) 한국잠사학회 2007 International Journal of Industrial Entomology Vol.8 No.2

Amylase isozyme based three multivoltine viz., N+p, Np, N+p(cho) and two bivoltine-D6+p, D6p syngenic lines (Syn. L) were developed from germplasm (GP) stocks Nistari (N) and D6 respectively. haemolymph isozyme pattern at pH 7.0 and 8.5 depicted a total 11 number (Amy1 to 6 at pH 7.0 and Amy1 to 5 at pH 8.5) of native proteins (NP) of various sizes are amylase isozyme expressers. Among eleven NPs, two NPs of 770 kDa (Amy6 at pH 7.0) and 376 kDa (Amy3 at pH 8.5) are a-amylase expressers and remaining NPs of 370, 364, 350, 329 and 274 kDa at pH 7.0 and 206, 292, 416, 725 kDa at pH 8.5 are β-amylase expressers. Accordingly, digestive juice amylase isozyme pattern at aforesaid pH also depicted a total number of 10 NPs (Amy1 to 5) at each pH 7.0 and 8.5 are amylase expressers of which NP of 387 kDa (Amy4 at pH 7.0) and 780 kDa (Amy5 at pH 8.5) are a-amylase expresser. Remaining NPs of 338,297 & 216 kDa at pH 7.0 and 370, 341, 329 &302 kDa at pH 8.5 are β-amylase expresser. Recurrent backcross lines (RBL) viz., N+pRBL and NpRBL were developed through introgression of high shell weight character (a multigenic trait) to be used further for congenic line (Con. L) development and to understand any association with introgressed character. Isozyme pattern in haemolymph of RBLs depicted only one α-amylase of 770 kDa at pH 7.0 and 376 kDa at pH 8.0 with three and four respective β-amylase bands but in bivoltine lines numbers of β-amylase bands vary between 1 to 2 at aforesaid pH. Variability was also observed in digestive juice of multivolitine and its RBLs but bivoltine lines express null activity at both pH except appearance of one very week α-amylase band D6+p at pH 8.5. Overall study suggests that not a single NP at both pH is common for expression of any band of amylase isozyme i.e., a totally different set of proteins are the amylase isozyme expresser at specific pH and no molecular factor of amylase is associated in developed RBLs which showed improvement on survival, single cocoon shell weight (SCSW) and single filament length over receptor parents.

Isoelectronic Pt(ii)- and Au(iii)-N-heterocyclic carbene complexes: a structural and biological comparison

Rana, Bidyut Kumar,Mishra, Snehasis,Sarkar, Deblina,Mondal, Tapan Kumar,Seth, Saikat K.,Bertolasi, Valerio,Das Saha, Krishna,Bielawski, Christopher W.,Isab, Anvarhusein A.,Dinda, Joydev The Royal Society of Chemistry 2018 NEW JOURNAL OF CHEMISTRY Vol.42 No.13

<P>To elucidate the intrinsic biological activities displayed by platinum <I>versus</I> gold-based organometallic reagents, the isoelectronic and isostructural square planar complexes [Pt(C∩N)(C)Cl][PF6] (2) and [Au(C∩N)(C)Cl][PF6]2 (3), which are supported by a common N-heterocyclic carbene, 1-methyl-2-pyridin-2-yl-2<I>H</I>-imidazo[1,5-<I>a</I>]pyridin-4-ylidene (1), were synthesized. The complexes were characterized using a range of spectroscopic techniques as well as single crystal X-ray diffraction and a series of computational studies were also performed to gain additional insight into their fundamental electronic bonding structures. The cytotoxicities of the complexes were tested <I>in vitro</I> against non-small lung carcinoma (A549), colorectal carcinoma (HCT-116) and human hepatocellular carcinoma (HepG2) cell lines. The measured IC50 values showed that the Au(iii)-NHC complex is more potent than its Pt analogue.</P>

DYNAMICAL STRUCTURE OF VISCOUS ACCRETION DISKS WITH SHOCKS

Das, Santabrata,Becker, Peter A.,Le, Truong IOP Publishing 2009 The Astrophysical journal Vol.702 No.1

<P>We develop and discuss global accretion solutions for viscous advection-dominated accretion flow (ADAF) disks containing centrifugally supported isothermal shock waves. The fact that such shocks can exist at all in ADAF disks is a new result. Interestingly, we find that isothermal shocks can form even when the level of viscous dissipation is relatively high. In order to better understand this phenomenon, we explore all possible combinations of the fundamental flow parameters, such as specific energy, specific angular momentum, and viscosity, to obtain the complete family of global solutions. This procedure allows us to identify the region of the parameter space where isothermal shocks can exist in viscous ADAF disks. The allowed region is maximized in the inviscid case, and it shrinks as the level of viscous dissipation increases. Adopting the canonical value gamma = 1.5 for the ratio of specific heats, we find that the shock region disappears completely when the Shakura-Sunyaev viscosity parameter alpha exceeds the critical value similar to 0.27. This establishes for the first time that steady ADAF disks containing shocks can exist even for relatively high levels of viscous dissipation. If an isothermal shock is present in the disk, it would have important implications for the acceleration of energetic particles that can escape to power the relativistic jets commonly observed around underfed, radio-loud black holes. In two specific applications, we confirm that the kinetic luminosity lost from the disk at the isothermal shock location is sufficient to power the observed relativistic outflows in M87 and Sgr A*.</P>

On energy and Laplacian energy of bipartite graphs

Das, K.Ch.,Mojallal, S.A.,Gutman, I. Elsevier [etc.] 2016 Applied Mathematics and Computation Vol.273 No.-

<P>Let G be a bipartite graph of order it with in edges. The energy epsilon(G) of G is the sum of the absolute values of the eigenvalues of the adjacency matrix A. In 1974, one of the present authors established lower and upper bounds for epsilon(G) in terms of 11, in, and detA. Now, more than 40 years later, we correct some details of this result and determine the extremal graphs. In addition, an upper bound on the Laplacian energy of bipartite graphs in terms of n, m, and the first Zagreb index is obtained, and the extremal graphs characterized. (C) 2015 Elsevier Inc. All rights reserved.</P>

a- and b-Amylase Isozyme Expresser Native Proteins in Tropical Silkworm Bombyx mori L.

G. K. Chattopadhyay,A. K. Verma,A. K. Sengupta,S. K. Das,S. Raje Urs 한국잠사학회 2004 International Journal of Industrial Entomology Vol.8 No.2

Oxide Scale Characterization and Study of Oxidation Kinetics in T91 Steel Exposed to Dry Air at High Temperatures (873–1073 K)

S. Das,S. Sanyal,P. Halder,A. Varma,Y. Ravi Kumar,S. Mandal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In this study, the oxidation response of a T91 steel in dry air environment has been investigated by performing cyclic oxidationtests at 873, 973 and 1073 K for a total duration of 1000 h with intermediate intervals. The temperature range for thisstudy is chosen to be higher than the operating temperature range of the alloy to accelerate the oxidation kinetics. Developinga comprehensive understanding of the mechanisms and kinetics involved at such accelerated oxidation environmentswould help to formulate better strategies for countering oxidation related failure events. The results of this study showedthat the oxidation rate is greatly influenced by temperature as well as exposure time, and follows a near-parabolic rate law. Characterization of the oxide scales revealed formation of dual oxide layers where the inner layer is primarily rich in Feand Cr, and the outer layer in Fe only. At 1073 K, formation of cracks can be observed in the oxide scales after 24 h, whichbecame more severe after 1000 h. The oxidation kinetics, when fitted to an Arrhenius type equation, can be associated withactivation energy (Q) and parabolic rate constant (kp) values. The Q values lie within 104–109 kJ/mol, whereas the kp valuesincrease with temperature due to increase in the reaction rate. The kinetic equation developed based on the Q and kp valuescan be used to predict the thickness (inner, outer and overall) of the oxide scales in T91 steel at any temperature and timewithin the studied ranges.