4. 3D flows past circular cylinder of low aspect ratio

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Mifepristone for cervical ripening and induction of labour

Background: The study was aimed to evaluate the efficacy of Mifepristone for induction of labour and in improving the Bishop score at term. The study also aimed to assess induction delivery interval and maternal and fetal outcomes with Mifepristone.Methods: The study was carried out on 200 pregnant females with 2 study groups of 100 each. Group A females received tablet Mifepristone 400mg and   Group B females received placebo. Results: Time interval between induction to onset of labour was 28 hours 54 min and 42 hours 18 min respectively in cases and control group. Mean induction delivery interval was 35 hours 38 min and 49 hours 52 minutes respectively in cases and control group. LSCS rate was less with Mifepristone group.Conclusions: This study showed that treatment with Mifepristone is a simple and effective method of inducing labour in women with term pregnancy with unripe cervix. The use of Mifepristone provides an interesting new alternative to classic uterotonic agents when induction is necessary. The potential advantage of Mifepristone over PGs or oxytocin requires further evaluation in scarred uterus

Phase stability and structural temperature dependence in sodium niobate: A high resolution powder neutron diffraction study

We report investigation of structural phase transitions in technologically important material sodium niobate as a function of temperature on heating over 300-1075 K. Our high resolution powder neutron diffraction data show variety of structural phase transitions ranging from non-polar antiferrodistortive to ferroelectric and antiferroelectric in nature. Discontinuous jump in lattice parameters is found only at 633 K that indicates that the transition of orthorhombic antiferroelectric P (space group Pbcm) to R (space group Pbnm) phase is first order in nature, while other successive phase transitions are of second order. New superlattice reflections appear at 680 K (R phase) and 770 K (S phase) that could be indexed using an intermediate long-period modulated orthorhombic structure whose lattice parameter along direction is 3 and 6 times that of the CaTiO3-like Pbnm structure respectively. The correlation of superlattice reflections with the phonon instability is discussed. The critical exponent ({\beta}) for the second order tetragonal to cubic phase transition at 950 K, corresponds to a value {\beta}$\approx 1/3$, as obtained from the temperature variation of order parameters (tilt angle and intensity of superlattice reflections). It is argued that this exponent is due to a second order phase transition close to a tricritical point. Based on our detailed temperature dependent neutron diffraction studies, the phase diagram of sodium niobate is presented that resolves existing ambiguities in the literature.Comment: 21 Pages, 8 Figure

Enhancement of bulk second-harmonic generation from silicon nitride films by material composition

We present a comprehensive tensorial characterization of second-harmonic generation from silicon nitride films with varying composition. The samples were fabricated using plasma-enhanced chemical vapor deposition, and the material composition was varied by the reactive gas mixture in the process. We found a six-fold enhancement between the lowest and highest second-order susceptibility, with the highest value of approximately 5 pm/V from the most silicon-rich sample. Moreover, the optical losses were found to be sufficiently small (below 6 dB/cm) for applications. The tensorial results show that all samples retain in-plane isotropy independent of silicon content, highlighting the controllability of the fabrication process.Comment: 4 pages, 3 figures, 2 tables; Re-submitted to Optics Letter

Transition Metal Chemistry of Oxime Containing Ligands: Part III-Complexes of Fe(II), Co(II) & Ni(II) with Pyridine-2-aldoxime & 6-Methylpyridine-2-aldoxime

696-69

Effects of magnetic doping and temperature dependence on phonon dynamics in CaFe\_{1-x}Co\_{x}AsF compounds (x = 0, 0.06, 0.12)

We report detailed measurements of composition as well as temperature dependence of the phonon density-of-states in a new series of FeAs compounds with composition CaFe1\_{1-x}Co\_{x}AsF (x = 0, 0.06, 0.12). The composition as well as temperature dependence of phonon spectra for CaFe\_{1-x}Co\_{x}AsF (x = 0, 0.06, 0.12) compounds have been measured using time of flight IN4C and IN6 spectrometers at ILL, France. The comparison of phonon spectra at 300 K in these compounds shows that acoustic phonon modes up to 12 meV harden in the doped compounds in comparison to the parent CaFeAsF. While intermediate energy phonon modes from 15 meV to 25 meV are also found to shift towards high energies only in the 12 % Co doped CaFeAsF compound. The experimental results for CaFe\_{1-x}Co\_{x}AsF (x = 0, 0.06, 0.12) are quite different from our previous phonon studies on parent and superconducting MFe2As2 (M=Ba, Ca, Sr) where low-energy acoustic phonon modes do not react with doping, while the phonon spectra in the intermediate range from 15 to 25 K are found to soften in these compounds. We argue that stronger spin phonon interaction play an important role for the emergence of superconductivity in these compounds. The lattice dynamics of CaFe\_{1-x}Co\_{x}AsF (x = 0, 0.06, 0.12) compounds is also investigated using the ab-initio as well as shell model phonon calculations. We show that the nature of the interaction between the Ca and the Fe-As layers in CaFeAsF compounds is quite different compared with our previous studies on CaFe2As2.Comment: 19 pages, 5 figure

Studies on Neutron, Photon (Bremsstrahlung) and Proton Induced Fission of Actinides and Pre-Actinides

We present the yields of various fission products determined in the reactor neutron, 3.7-18.1 MeV quasi-mono energetic neutron, 8-80 MeV bremsstrahlung and 20-45 MeV proton induced fission of 232Th and 238u using radiochemical and off-line beta or gamma ray counting. The yields of the fission products in the bremsstrahlung induced fission natPb and 209Bi with 50-70 MeV and 2.5 GeV based on off-line gamma ray spectrometric technique were also presented. From the yields of fission products, the mass chains yields were obtained using charge distribution correction. From the mass yield distribution, the peak-to-valley (P/V) ratio was obtained. The role of excitation energy on the peak-to-valley ratio and fine structure such as effect of shell closure proximity and even-odd effect of mass yield distribution were examined. The higher yields of the fission products around A=133-134, 138-140 and 143-144 and their complementary products explained from the nuclear structure effect and role of standard I and II mode of asymmetric fission. In the neutron, photon (bremsstrahlung) and proton induced fission, the asymmetric mass distribution for actinides (Th, u) and symmetric distribution for pre-actinides (Pb, Bi) were explained from different type of potential fission barrier