1,823 research outputs found

    STATISTICAL MEDIA OPTIMIZATION FOR LUTEIN PRODUCTION FROM MICROALGAE Auxenochlorella protothecoides SAG 211-7A

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    In this study, the heterotrophic production potential of the secondary carotenoid lutein by the green microalgae Auxenochlorella protothecoides SAG 211-7a was investigated. A sequential statistical technique was applied to optimize modified bold’s basal media (MBB) to enhance the lutein production from microalgae Auxenochlorella protothecoides SAG 211-7a. Taguchi orthogonal array method was applied to select the various independent variables which affect the lutein production. It showed that sucrose, yeast extract, MgSO4.7H2O and EDTA were the significant factors affect the lutein production. Further, to increase the lutein yield and to study the interaction between these factors response surface methodology (RSM) was employed. The statistical model was validated with respect to lutein production under the conditions predicted by the model containing sucrose 14.0 g/l, yeast extract 3.0 g/l, MgSO4.7H2O 0.8 g/l and EDTA 0.76 g/l. The production of lutein obtained experimentally using the above medium was 1303 ± 25.32 μg/l, which is in correlation with the predicted value of 1337.21 g/l by the RSM regression study. Thus after sequential statistical media optimization strategy a 5-fold enhancement in lutein production was achieved

    Primers and Probe to Identify Mycobacterium Tuberculosis Complex

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    Methods and nucleic acids for rapid, reliable and sensitive detection of Mycobacterium tuberculosis (MTB) complex pathogen in a biological sample. Oligonucleotides are provided which amplify MTB DNA and which are useful in carrying out real time PCR of DNA obtained from formalin-fixed and paraffin-embedded tissue samples

    Computation of optimal singular controls

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    Computation of optimal singular control

    Release of β-galactosidase by Permeabilization of Indigenously Isolated Lactobacillus acidophilus Using Lysozyme

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    Enzymatic lysis, using lysozyme, has been shown in this paper to be an effective cell lysis method to release β-galactosidase from Lactobacillus acidophilus indigenously isolated from Eleusine coracana. The lytic process was developed using response surface methodology (RSM) to optimize lysozyme concentration, cell density and incubation time critical for the release of β-galactosidase. The optimized permeabilization condition (lysozyme: 33.63 · 104 U mL–1; cell density: 4.7 % w/v on wet basis; incubation time: 10h 30min.) resulted in 1.2 fold increase in release of β-galactosidase when compared with an optimized ultrasonication process. These optimized conditions were used to determine the release constants of β-galactosidase and total protein release as a function of temperature. The enzyme and protein release constants were used further to calculate the location factor of β-galactosidase

    Numerical investigation of cloud cavitation and cavitation noise on a hydrofoil section

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    Partial cavitating flow and cloud cavitation on a hydrofoil section are numerically investigated. A fully compressible, density based homogeneous equilibrium model is employed along with a RANS turbulence model and high-order numerical methods based on a sixthorder central compact scheme and localized artificial diffusivity scheme are used to resolve the cavitating flow and pressure waves generated by cloud cavitation. Predicted results compare well with the experimental measurements for steady/unsteady partial cavitating flows on a NACA66 hydrofoil at cavitation number, ?=1.0-1.4 and angle of attack 6 and 8 degree. Detailed experimental data from the work of Leroux et al. were provided by Prof. J.-A. Astolfi at Institut de Recherche de l Ecole Navale, France. Numerical visualizations of cloud cavity evolution and surface pressure signals show relatively good agreement with the experimental data. The re-entrant jet flow and pressure wave generated by collapse of cloud cavity are closely investigated. The mechanism associated with two different unsteady dynamics of cloud cavitation observed in previous numerical/experimental study for angle of attack 6 and 8 degree are further explored using the present computational results. The pressure pulse generated by the collapse of bubble cloud and the flow-blockage effect caused by a large cavity cloud are found to be responsible for the shifting of cloud cavitation dynamics.http://deepblue.lib.umich.edu/bitstream/2027.42/84259/1/CAV2009-final62.pd

    Vortex-induced disturbance field in a compressible shear layer

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    The disturbance field induced by a small isolated vortex in a compressible shear layer is studied using direct simulation in a convected frame. The convective Mach number, M(sub c), is varied from 0.1 to 1.25. The vorticity perturbation is rapidly sheared by the mean velocity gradient. The resulting disturbance pressure field is observed to decrease both in magnitude and extent with increasing M(sub c), becoming a narrow transverse zone for M(sub c) greater than 0.8. A similar trend is seen for the perturbation velocity magnitude and for the Reynolds shear stress. By varying the vortex size, we verified that the decrease in perturbation levels is due to the mean-flow Mach number and not the Mach number across the vortex. At high M(sub c), the vortex still communicates with the edges of the shear layer, although communication in the mean-flow direction is strongly inhibited. The growth rate of perturbation kinetic energy declines with M(sub c) primarily due to the reduction in shear stress. For M(sub c) greater than or equal to 0.6, the pressure dilatation also contributes to the decrease of growth rates. Calculation of the perturbation field induced by a vortex doublet revealed the same trends as in the single-vortex case, illustrating the insensitivity of the Mach-number effect to the specific form of initial conditions

    Stacking faults in double hexagonal close-packed crystals

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    Possible deviations in the regular ....ABACA.... sequence of stacking (0004) close-packed planes in the double hexagonal close-packed (d.h.c.p.) structure have been considered. Six intrinsic and one extrinsic type stacking faults have been suggested. The schemes of stacking sequences have been usefully considered in terms of the configurational symbols suggested by Jagodzinski. Extending the Hirth and Lothe procedure, estimates of theoretical fault energies are given in terms of the number of pairs of planes of separation N which are not in the shceme of perfect structure sequence. Relative fault energies have been arrived at reckoning only the first and second nearest neighbour interactions for three ideal situations: (a) the transformation energy of d.h.c.p. structure to either f.c.c. or h.c.p. structure is the same; (b) d.h.c.p. ⇌ f.c.c. transformation occurs; and (c) d.h.c.p. ⇌ h.c.p. transformation occurs

    n-fold sub-implicative ideals and n-fold sub-commutative ideals of BCI-algebras

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