Probabilistic analysis of bladed turbine disks and the effect of mistuning

Probabilistic assessment of the maximum blade response on a mistuned rotor disk is performed using the computer code NESSUS. The uncertainties in natural frequency, excitation frequency, amplitude of excitation and damping are included to obtain the cumulative distribution function (CDF) of blade responses. Advanced mean value first order analysis is used to compute CDF. The sensitivities of different random variables are identified. Effect of the number of blades on a rotor on mistuning is evaluated. It is shown that the uncertainties associated with the forcing function parameters have significant effect on the response distribution of the bladed rotor

Novel Biologically Potent Diorganosilicon(IV) Complexes of Indole-2,3-Dione Derivatives

The aim of the present study is to synthesize some novel ecofriendly fungicides and bactericides of indole-2,3-dione derivatives, having important pharmacodynamic significance. The ligands used in the present account are derived by the condensation of 1,3-dihydro-3-[2-(phenyl)-2-oxoethylidene]-2H-indol-2- one, 1,3-dihydro-3-[2-(4-nitrophenyl)-2-oxoethylidene]-2H-indol-2-one and 1,3-dihydro-3-[2-(4-nitro-3-methylphenyl)- 2-oxoethylidene]-2H-indol-2-one with hydrazinecarboxamide and hydrazinecarbothioamide. These imines, on interaction with diorganosilicon(IV) chlorides, yield complexes having Si–O or Si–S and Si←N bonds. The structure of these compounds have been elucidated by elemental microanalyses and spectral [(UV), (IR), 1H, 13C and 29Si NMR)] studies which unerringly point to a trigonal bipyramidal and octahedral geometries for unimolar and bimolar reactions, respectively. The potency of the synthesized compounds have been assessed by growth inhibiting potential of the complexes against variety of fungal and bacterial strains and male albino rats. The results of these biological studies have been compared with the standard fungicide, Bavistin. The studies demonstrate that, 1,3-dihydro-3-[2-(4-nitrophenyl)-2-oxoethylidene]-2H-indol-2-onehydrazincarbothioamide and its diphenylsilicon(IV) complexes have comparable antimicrobial activity and are less toxic to male albino rats than Bavistin

Hikami-Larkin-Nagaoka (HLN) Fitting of Magneto Transport of Bi2Se3 Single Crystal in Different Magnetic Field Ranges

We report the detailed study of structural micro-structuraland high magnetic field magneto transport propertiesof Bi2Se3single crystal. Bi2Se3 single crystal is grown through conventional solid-state reaction route via the self-flux method. Rietveld analysis on Powder X-ray Diffraction showed that the studied Bi2Se3 crystal is crystallized in single-phase without any impurity. The surface morphology analyzed through Scanning Electron Microscopy study which shows that as-grown single crystal exhibit layered type structure and the quantitative weight of the atomic constituents (Bi and Se) are found to be closeto the stoichiometric amount in energy-dispersive X-ray spectroscopy analysis. Low temperature (2.5K) magneto-resistance (MR) exhibited a v-type cusp around origin at lower magnetic field, which is the sign of weak anti-localization effect. Further, Bi2Se3 single crystal magneto conductivity data is fitted by well-known HLN equation in different magnetic field range of 2Tesla, 4Tesla and 6Tesla and the resultant found that the conduction mechanism of Bi2Se3 is dominated by WAL state.Comment: 4 Pages Text + Fig

Two Foraging Algorithms for Robot Swarms Using Only Local Communication

Large collections of robots have the potential to perform tasks collectively using distributed control algorithms. These algorithms require communication between robots to allow the robots to coordinate their behavior and act as a collective. In this paper we describe two algorithms which allow coordination between robots, but do not require physical environment marks such as pheromones. Instead, these algorithms rely on simple, local, low bandwidth, direct communication between robots. We describe the algorithms and measure their performance in worlds with and without obstacles.Engineering and Applied Science

Performance Evaluation of Image Steganography using Hybrid Technique in Frequency Domain

Protection of digital multimedia content has become an increasingly important issue for content owners and service providers. The major methodology for protection of some digital content is- Steganography. Image Steganography is a process where information such as name of the creator, status, recipient, etc. is stored in the form of an image which is embedded into the host image in such a way that it will remain invisible or undetectable to a normal person. Only the intended recipient would be able to detect and remove the secret image. There are three main mutually conflicting properties of information hiding schemes: Imperceptibility, Robustness and Capacity. This paper measures the imperceptibility and robustness of the proposed system in terms of two parameters- PSNR and NC respectively. Now, while transmitting the image having some secret information embedded in the cover image, some attacks may arise on it which would degrade the quality of the secret image while extracting it. The technique is again tested against different attacks with varying attack intensities

Effect of Common Vegetables on Thyroid Function in Rats-A Preliminary Study

Goitrogenic potency of some vegetables of Delhi were studied in rats. Adult male rats were fed separately on thiouracil, thiocyanate and extracts of carrot, cabbage and turnip procured from Delhi market for 26 days. Cabbage and turnip showed high thiocyanate contents while carrot did not show any measurable amount. Appreciable increase in thyroid weight to body weight ratio, plasma thiocyanate, plasma/sup 131/1 contents and protein bound/sup 131/ 1 or plasma were observed in all groups of experimental, rats, except carrot. Results indicated goitrogenic nature of cabbage and turnip in rats

Essential role of MED1 in the transcriptional regulation of ER-dependent oncogenic miRNAs in breast cancer

Mediator complex has been extensively shown to regulate the levels of several protein-coding genes; however, its role in the regulation of miRNAs in humans remains unstudied so far. Here we show that MED1, a Mediator subunit in the Middle module of Mediator complex, is overexpressed in breast cancer and is a negative prognostic factor. The levels of several miRNAs (miR-100-5p, -191-5p, -193b-3p, -205-5p, -326, -422a and -425-5p) were found to be regulated by MED1. MED1 induces miR-191/425 cluster in an estrogen receptor-alpha (ER-\u3b1) dependent manner. Occupancy of MED1 on estrogen response elements (EREs) upstream of miR-191/425 cluster is estrogen and ER-\u3b1-dependent and ER-\u3b1-induced expression of these miRNAs is MED1-dependent. MED1 mediates induction of cell proliferation and migration and the genes associated with it (JUN, FOS, EGFR, VEGF, MMP1, and ERBB4) in breast cancer, which is abrogated when used together with miR-191-inhibition. Additionally, we show that MED1 also regulates the levels of direct miR-191 target genes such as SATB1, CDK6 and BDNF. Overall, the results show that MED1/ER-\u3b1/miR-191 axis promotes breast cancer cell proliferation and migration and may serve as a novel target for therapy

Probabilistic evaluation of uncertainties and risks in aerospace components

This paper summarizes a methodology developed at NASA Lewis Research Center which computationally simulates the structural, material, and load uncertainties associated with Space Shuttle Main Engine (SSME) components. The methodology was applied to evaluate the scatter in static, buckling, dynamic, fatigue, and damage behavior of the SSME turbo pump blade. Also calculated are the probability densities of typical critical blade responses, such as effective stress, natural frequency, damage initiation, most probable damage path, etc. Risk assessments were performed for different failure modes, and the effect of material degradation on the fatigue and damage behaviors of a blade were calculated using a multi-factor interaction equation. Failure probabilities for different fatigue cycles were computed and the uncertainties associated with damage initiation and damage propagation due to different load cycle were quantified. Evaluations on the effects of mistuned blades on a rotor were made; uncertainties in the excitation frequency were found to significantly amplify the blade responses of a mistuned rotor. The effects of the number of blades on a rotor were studied. The autocorrelation function of displacements and the probability density function of the first passage time for deterministic and random barriers for structures subjected to random processes also were computed. A brief discussion was included on the future direction of probabilistic structural analysis

Antiandrogen and Antimicrobial Aspects of Coordination Compounds of Palladium(II), Platinum(II) and Lead(II)

Synthesis, characterization and antimicrobial activities of an interesting class of biologically potent macrocyclic complexes have been carried out. All the complexes have been evaluated for their antimicrobial effects on different species of pathogenic fungi and bacteria. The testicular sperm density, testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemical parameters of reproductive organs have been examined and discussed. The resulting biologically active [M(MaLn)(R2)]Cl2 and [Pb(MaLn)(R2)X2] (where, M = PdII or PtII and X = Cl or NO3) type of complexes have been synthesized by the reactions of macrocyclic ligands (MaLn) with metal salts and different diamines in 1:1:1 molar ratio in methanol. Initially the complexes were characterized by elemental analyses, molecular weight determinations and conductivity measurements. The mode of bonding was established on the basis of IR, 1H NMR, 13C NMR, 195Pt NMR, 207Pb NMR, XRD and electronic spectral studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by benzil moieties. IR spectra suggest that the pyridine nitrogen is not coordinating. The palladium and platinum complexes exhibit tetracoordinated square-planar geometry, whereas a hexacoordinated octahedral geometry is suggested for lead complexes