Effects of Nanodots Shape and Lattice Constants on the Spin Wave Dynamics of Patterned Permalloy Dots

Micromagnetic simulations studies on Permalloy (Ni80Fe20) nanodot with different shape and edge-to-edge separation (s) down to 25nm arranged in square lattice are reported. We observe the significant variation of spin-wave (SW) dynamics of nanodots of different shapes (triangular, diamond and hexagon) and of fixed dot diameter 100nm with varying s. Modes for single dot are transformed in an array into multiple quantized, edge and centre modes for different shapes and edge-to-edge separations, with different spin wave frequencies and peak intensities. Specifically, in the triangular dot sample, a broad range of mode frequencies is observed with highest SW frequency 14.7 GHz. For separation less than 100nm, the SW frequencies undergoes significant modification due to the varying nature of the magnetostatic and dipolar interaction in the array while for separation above 100nm, the SW frequency mostly remain constant. The power profiles confirm the nature of the observed modes. The spatial profiles of magnetostatic field are determined by a combination of internal magnetic-field profiles within the nanodots and the magnetostatic fields within the lattice. The inter-dots interaction of magnetostatic field shows dipolar and quadrupole contributions for all the shapes. Interestingly, vortex states with shifted core and polarity are observed in the array for all the shapes at Hbias = 0. Our results provide important understanding about the tunability of SW spectra in the array of triangular, diamond and hexagon shaped nanoelements.Comment: 13 pages, 8 figure

Chemistry of some ruthenium phenolates: synthesis, structure and redox properties

Reaction of three phenolate ligands, viz. 2,4,6-tribromophenol (HL1, where H stands for the phenolic proton), 2-nitrophenol (HL2) and 2,4,6-trinitrophenol (HL3O), with [Ru(PPh3)3Cl2] in a 2¦1 molar ratio in the presence of a base gives complexes of type [Ru(PPh3)2(L)2] (L=L1, L2 and L3). The 2,4,6-tribromophenolate ligand (L1) binds to ruthenium as a bidentate O,Br-donor, while the 2-nitrophenolate ligand (L2) acts as a bidentate O,O-donor. 2,4,6-Trinitrophenol (HL3O) undergoes oxygen loss from one nitro group at the ortho position and coordinates to ruthenium in the 2-nitroso-4,6-dinitrophenolate (L3) form through the nitroso nitrogen and phenolate oxygen. The structures of the [Ru(PPh3)2(L1)2] and [Ru(PPh3)2(L3)2] complexes have been solved by X-ray crystallography. In [Ru(PPh3)2(L1)2] the coordination sphere around ruthenium is O2P2Br2 with a trans-cis-cis disposition of the three sets of donor atoms, respectively. In [Ru(PPh3)2(L3)2] ruthenium has a N2O2P2 coordination sphere with a cis-cis-trans arrangement of the three sets of donor atoms, respectively. The [Ru(PPh3)2(L)2] complexes are diamagnetic (low-spin d6, S=0) and in acetonitrile solution show intense MLCT transitions in the visible region. Cyclic voltammetry on the [Ru(PPh3)2(L)2] complexes shows a reversible ruthenium(II)-ruthenium(III) oxidation within 0.63-0.71 V versus SCE followed by an irreversible ruthenium(III)-ruthenium(IV) oxidation near 1.5 V versus SCE

Non-linear revenue creating business platform for IT service companies using cloud computing

Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 63).The Indian Information Technology (IT) & Business process outsourcing (BPO) companies are going through an inflection point. They have been growing revenue by over 20% on a yearly basis for the last decade. This revenue growth has been fueled by a proportionate increase in employee headcount. Their ability to maintain the growth rate is in question, partly due to the difficultly in increasing the headcount and partly due to competition from multinational IT Service companies growing their business in India. In order to continue to grow, the Indian IT companies need to change their business model and look for nonlinear revenue growth, which is independent of the resource deployed or effort spent. Cloud computing provides a new strategic option for growth for the Indian IT-BPO companies. This thesis looks into Business Service Platform based on cloud computing and how the IT companies can leverage it to generate nonlinear revenue. It also explores ways to implement the business platform, along with risks and challenges involved. The IT companies would need to change their current sales and marketing process, along with talent recruitment guidelines and training content in order to successfully roll out the platforms, on which its future growth is dependent.by Prasanta Sinha.S.M

Activating ZnO nanorods photoanodes in visible light by CdS surface sensitiser

Thin films of c-axis aligned uniform ZnO nanorods (NRs) were fabricated on to fluorine-doped tin oxide-coated soda lime glass substrate by a two-step chemical route. Thereafter ZnO NRs/CdS core shell structures were successfully synthesised by depositing CdS layer on top of vertically aligned ZnO NRs using less hazardous nanocrystal layer deposition technique. The presence of CdS in ZnO NRs/CdS core shell structures was confirmed by energy dispersive X-ray analysis. Examination of structure and morphology of the fabricated films by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) revealed that both films have one-dimensional hexagonal wurtzite structure. Optical properties evaluated from ultraviolet-visible and photoluminescence spectra demonstrated better photo response of ZnO NRs/CdS core shell structure with respect to bare ZnO NR structure. Optical to chemical conversion efficiency of ZnO NRs/CdS photoanode was found to be similar to 1.75 times higher than bare ZnO NRs photoanode in photo electrochemical water splitting under visible light

Cystathionine β-synthase T833C/844INS68 polymorphism: a family-based study on mentally retarded children

BACKGROUND: Cystathionine β-synthase (CBS) mediates conversion of homocysteine to cystathionine and deficiency in enzyme activity may lead to hyperhomocysteinemia/homocystinuria, which are often associated with mental retardation (MR). A large number of polymorphisms have been reported in the CBS gene, some of which impair its activity and among these, a T833C polymorphism in cis with a 68 bp insertion at 844 in the exon 8 is found to be associated with mild hyperhomocysteinemia in different ethnic groups. METHODS: The present study is aimed at investigating the association between T833C/844ins68 polymorphism and MR. One hundred and ninety MR cases were recruited after psychometric evaluation. Hundred and thirty-eight control subjects, two hundred and sixty-seven parents of MR probands and thirty cardiovascular disorder (CVD) patients were included for comparison. Peripheral blood was collected after obtaining informed written consent. The T833C/844ins68 polymorphism was investigated by PCR amplification of genomic DNA and restriction fragment length polymorphism analysis, followed by statistical analysis. RESULTS: The genotypic distribution of the polymorphism was within the Hardy-Weinberg equilibrium. A slightly increased genotypic frequency was observed in the Indian control population as compared to other Asian populations. Both haplotype-based haplotype relative risk analysis and transmission disequilibrium test reveled lack of association of the T833C/844ins68 polymorphism with MR; nevertheless, the relative risk calculated was higher (>1) and in a limited number of informative MR families, preferential transmission of the double mutant from heterozygous mothers to the MR probands was noticed (χ(2 )= 4.00, P < 0.05). CONCLUSION: This is the first molecular genetic study of CBS gene dealing with T833C/844ins68 double mutation in MR subjects. Our preliminary data indicate lack of association between T833C/844ins68 polymorphism with MR. However, higher relative risk and biased transmission of the double mutation from heterozygous mothers to MR probands are indicative of a risk of association between this polymorphism with mental retardation

A Comparative Spectrophotometric Study Using Ferrozine and 1,10-Ortho-phenanthroline to Evaluate the Iron Redox Ratio (Fe2+/Sigma Fe) in Glass Prepared by Microwave Heating

In the present study, Fe-doped barium borosilicate glass has been melted at 1250 degrees C under microwave heating. The iron redox ratio (Fe2+/total Fe) in the glass is investigated by two spectrophotometric methods. A novel decomposition technique has been optimized to measure the ferrous oxidation state in glass. Ferrozine was chosen as a specific complexing reagent; it forms a deep violet color complex with Fe2+ and has a broad absorbance peak centered at 562 nm. 1,10-ortho-phenanthroline develops an orange color complex with Fe2+ (having an absorbance peak centered at similar to 510 nm) and has been used to determine ferrous ion in glass. Both the methods are compared and the estimated redox ratio was found to be higher in the ferrozine method. The error limit of measurement has been determined as 0.012 and 0.023 for the ferrozine and 1,10-ortho-phenanthroline methods, respectively

Effect of charge and spin multiplicity on hyperpolarizabilities of donor-acceptor substituted polyenes

Theoretical studies of the ground state structure and nonlinear optical (NLO) properties of a number of donor-acceptor substituted singlet and triplet (neutral) and doublet (mono-positive and mono-negative) polyenes have been carried out. The variation of NLO property of the investigated molecules has been explained by using previously derived relationships between the different order polarizabilities and ground state dipole moment obtained in the framework of the standard sum-over-state expressions of Orr-Ward-Bishop and the generalized Thomas-Kuhn sum rule. The effect of charge and spin multiplicity on the molecular hyperpolarizabilities have been discussed in terms of relative changes of polarizability and ground state dipole moment. Among the investigated polyenes, the isotropic polarizability and the second-hyperpolarizability are predicted to be larger for the doublet anions in which the NH2 group is pyramidal. The position of nitrogen atom in the p-conjugative path strongly modulates the magnitudes of both the first- and second-hyperpolarizabilities of the investigated polyenes

Identification of RAPD and SCAR markers associated with yield traits in the Indian tropical tasar silkworm Antheraea mylitta drury

Abstract The tropical tasar silkworm, Antheraea mylitta, is a semi-domesticated vanya silk-producing insect of high economic importance. To date, no molecular marker associated with cocoon and shell weights has been identified in this species. In this report, we identified a randomly amplified polymorphic DNA (RAPD) marker and examined its inheritance, and also developed a stable diagnostic sequence-characterized amplified region (SCAR) marker. Silkworms were divided into groups with high (HCSW) and low (LCSW) cocoon and shell weights, and the F 2 progeny of a cross between these two groups were obtained. DNA from these silkworms was screened by PCR using 34 random primers and the resulting RAPD fragments were used for cluster analysis and discriminant function analysis (DFA). The clustering pattern in a UPGMA-based dendogram and DFA clearly distinguished the HCSW and LCSW groups. Multiple regression analysis identified five markers associated with cocoon and shell weights. The marker OPW16 905 bp showed the most significant association with cocoon and shell weights, and its inheritance was confirmed in F 2 progeny. Cloning and sequencing of this 905 bp fragment showed 88% identity between its 134 nucleotides and the Bmc-1/Yamato-like retroposon of A. mylitta. This marker was further converted into a diagnostic SCAR marker (SCOPW 16 826 bp ). The SCAR marker developed here may be useful in identifying the right parental stock of tasar silkworms for high cocoon and shell weights in breeding programs designed to enhance the productivity of tasar silk

Eff ect of participatory women’s groups facilitated by Accredited Social Health Activists on birth outcomes in rural eastern India: a cluster-randomised controlled trial

Background A quarter of the world’s neonatal deaths and 15% of maternal deaths happen in India. Few community-based strategies to improve maternal and newborn health have been tested through the country’s government-approved Accredited Social Health Activists (ASHAs). We aimed to test the eff ect of participatory women’s groups facilitated by ASHAs on birth outcomes, including neonatal mortality. Methods In this cluster-randomised controlled trial of a community intervention to improve maternal and newborn health, we randomly assigned (1:1) geographical clusters in rural Jharkhand and Odisha, eastern India to intervention (participatory women’s groups) or control (no women’s groups). Study participants were women of reproductive age (15–49 years) who gave birth between Sept 1, 2009, and Dec 31, 2012. In the intervention group, ASHAs supported women’s groups through a participatory learning and action meeting cycle. Groups discussed and prioritised maternal and newborn health problems, identifi ed strategies to address them, implemented the strategies, and assessed their progress. We identifi ed births, stillbirths, and neonatal deaths, and interviewed mothers 6 weeks after delivery. The primary outcome was neonatal mortality over a 2 year follow up. Analyses were by intention to treat. This trial is registered with ISRCTN, number ISRCTN31567106. Findings Between September, 2009, and December, 2012, we randomly assigned 30 clusters (estimated population 156 519) to intervention (15 clusters, estimated population n=82 702) or control (15 clusters, n=73 817). During the follow-up period (Jan 1, 2011, to Dec 31, 2012), we identifi ed 3700 births in the intervention group and 3519 in the control group. One intervention cluster was lost to follow up. The neonatal mortality rate during this period was 30 per 1000 livebirths in the intervention group and 44 per 1000 livebirths in the control group (odds ratio [OR] 0.69, 95% CI 0·53–0·89). Interpretation ASHAs can successfully reduce neonatal mortality through participatory meetings with women’s groups. This is a scalable community-based approach to improving neonatal survival in rural, underserved areas of India