Calculation of Weibull strength parameters and Batdorf flow-density constants for volume- and surface-flaw-induced fracture in ceramics

The calculation of shape and scale parameters of the two-parameter Weibull distribution is described using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. Detailed procedures are given for evaluating 90 percent confidence intervals for maximum likelihood estimates of shape and scale parameters, the unbiased estimates of the shape parameters, and the Weibull mean values and corresponding standard deviations. Furthermore, the necessary steps are described for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull distribution. It also shows how to calculate the Batdorf flaw-density constants by uing the Weibull distribution statistical parameters. The techniques described were verified with several example problems, from the open literature, and were coded. The techniques described were verified with several example problems from the open literature, and were coded in the Structural Ceramics Analysis and Reliability Evaluation (SCARE) design program

Radiation Pressure Induced Instabilities in Laser Interferometric Detectors of Gravitational Waves

The large scale interferometric gravitational wave detectors consist of Fabry-Perot cavities operating at very high powers ranging from tens of kW to MW for next generations. The high powers may result in several nonlinear effects which would affect the performance of the detector. In this paper, we investigate the effects of radiation pressure, which tend to displace the mirrors from their resonant position resulting in the detuning of the cavity. We observe a remarkable effect, namely, that the freely hanging mirrors gain energy continuously and swing with increasing amplitude. It is found that the `time delay', that is, the time taken for the field to adjust to its instantaneous equilibrium value, when the mirrors are in motion, is responsible for this effect. This effect is likely to be important in the optimal operation of the full-scale interferometers such as VIRGO and LIGO.Comment: 27 pages, 11 figures, RevTex styl

Is low amniotic fluid index an indicator of fetal distress and hence delivery?

Background: Amniotic fluid Index (AFI) is an indicator of fetal well-being. Low AFI is considered to be one of the indications for delivery as it may be associated with fetal distress and birth asphyxia. We sought to determine whether low AFI is an indicator of fetal compromise and an indication to deliver.Methods: This prospective, observational study was conducted at Department of Obstetrics & Gynecology, KMC, Manipal University, India, between August 2013 and Aug 2014. A total of 150 subjects that had induced labor or direct caesarean section for various indications and also having low-normal (5-8) / low (<5) AFI, were recruited. Subjects with fetal anomalies were excluded. Outcome variables studied were, fetal distress in labor, thick meconium stained amniotic fluid, mode of delivery in induced labor, perinatal asphyxia, and respiratory distress syndrome.Results: Out of 150 subjects, 68 (45.4%) had low and 82 (54.6%) had low-normal AFI. Both the groups were matched for demographic characteristics and confounding factors for neonatal outcome. In low AFI group the incidence of Low APGAR (11.7%), perinatal asphyxia (11.7%) and RDS (16.1%) were significantly higher compared to those in low-normal group (3.6%, 1.2% and 2.4% respectively) p = 0.057, 0.006 and 0.002. There was no significant difference between the groups with respect to mode of delivery when labor was induced.Conclusions: Low AFI, especially when it is <5, is an indicator of fetal compromise and one may anticipate perinatal asphyxia and RDS. Hence it is prudent to contemplate delivery when the AFI is between 5 and 8

Supersolid and solitonic phases in one-dimensional Extended Bose-Hubbard model

We report our findings on quantum phase transitions in cold bosonic atoms in a one dimensional optical lattice using the finite size density matrix renormalization group method in the framework of the extended Bose-Hubbard model. We consider wide ranges of values for the filling factors and the nearest neighbor interactions. At commensurate fillings, we obtain two different types of charge density wave phases and a Mott insulator phase. However, departure from commensurate fillings yield the exotic supersolid phase where both the crystalline and the superfluid orders coexist. In addition, we obtain signatures for solitary waves and also superfluidity.Comment: 7 pages, 11 figure

Cloud Computing Security Issues - Challenges and Opportunities

Cloud computing services enabled through information communication technology delivered to a customer as services over the Internet on a leased basis have the capability to extend up or down their service requirements or needs. In this model, the infrastructure is owned by a third party vendor and the cloud computing services are delivered to the requested customers. Cloud computing model has many advantages including scalability, flexibility, elasticity, efficiency, and supports outsourcing non-core activities of an organization. Cloud computing offers an innovative business concept for organizations to adopt IT enabled services without advance investment. This model enables convenient, on-request network accessibility to a shared pool of IT computing resources like networks, servers, storage, applications, and services. Cloud computing can be quickly provisioned and released with negligible management exertion or service provider interaction. Even though organizations get many benefits of cloud computing services, many organizations are slow in accepting cloud computing service model because of security concerns and challenges associated with management of this technology. Security, being the major issues which hinder the growth of cloud computing service model due to the provision of handling confidential data by the third party is risky such that the consumers need to be more attentive in understanding the risks of data breaches in this new environment. In this paper, we have discussed the security issues, the challenges and the opportunities in the adoption and management of cloud computing services model in an organization

Density wave and supersolid phases of correlated bosons in an optical lattice

Motivated by the recent experiment on the Bose-Einstein condensation of $^{52}$Cr atoms with long-range dipolar interactions (Werner J. et al., Phys. Rev. Lett., 94 (2005) 183201), we consider a system of bosons with repulsive nearest and next-nearest neighbor interactions in an optical lattice. The ground state phase diagram, calculated using the Gutzwiller ansatz, shows, apart from the superfluid (SF) and the Mott insulator (MI), two modulated phases, \textit{i.e.}, the charge density wave (CDW) and the supersolid (SS). Excitation spectra are also calculated which show a gap in the insulators, gapless, phonon mode in the superfluid and the supersolid, and a mode softening of superfluid excitations in the vicinity of the modulated phases. We discuss the possibility of observing these phases in cold dipolar atoms and propose experiments to detect them

Estudio de la Lidocaína al 0,5% y en Combinación de Lidocaína al 0,25% con Fentanilo y Vecuronio en Anestesia Regional Intravenosa para Cirugías de Miembros Superiores

ResumenJustificativa y objetivosLa anestesia regional intravenosa (ARIV) para cirugías de miembros superiores con la tradicional dosis alta de lidocaína, puede conllevar a efectos colaterales que amenazan la vida. Para evitar esos efectos colaterales potencialmente amenazadores, muchas técnicas modificadas de ARIV fueron experimentadas con el uso de una dosis baja de lidocaína, relajante muscular y opioide.Materiales y métodosEl presente estudio se hizo con 60 pacientes no medicados previamente, con clasificación ASA 1-2, para comparar las características sensoriales y motoras, los parámetros cardiorrespiratorios y los efectos colaterales durante el período intraoperatorio y de deflación pos torniquete, entre los pacientes que recibieron 40mL de lidocaína al 0,5% sola (n = 30) y los que recibieron una combinación de 40mL de lidocaína al 0,25% con 0,05mg de fentanilo y 0,5mg de vecuronio (n = 30) en ARIV para cirugías ortopédicas de miembros superiores. Los resultados se analizaron usando el teste t de Student pareado para identificar la significancia estadística. Resultado: La diferencia entre los dos grupos con relación al tiempo promedio de inicio y completo bloqueo sensitivo y motor, fue estadísticamente significativo. Sin embargo, hubo un completo bloqueo sensitivo y motor en ambos grupos 15 minutos después de la inyección de la solución anestésica. Conclusiones: Aunque la pequeña demora observada al inicio y durante la obtención completa de los bloqueos sensitivo y motor, teóricamente pueda atrasar el inicio de la operación entre 10 y 15 minutos, clínicamente ese tiempo se gastaría en la preparación del campo quirúrgico. Por tanto, esa combinación puede ser usada con seguridad y eficacia en la anestesia regional intravenosa para las cirugías ortopédicas de miembros superiores con menor posibilidad de toxicidad anestésica local

Synthesis, Structure, Electrochemistry, and Spectral Characterization of Bis-Isatin Thiocarbohydrazone Metal Complexes and Their Antitumor Activity Against Ehrlich Ascites Carcinoma in Swiss Albino Mice

The synthesis, structure, electrochemistry, and biological studies of Co(II), Ni(II), Cu(II), and Zn(II) complexes of thiocarbohydrazone ligand are described. The ligand is synthesized starting from thiocarbohydrazide and isatin. It is evident from the IR data that in all the complexes, only one part of the ligand is coordinated to the metal ion resulting mononuclear complexes. The ligand coordinates essentially through the carbonyl oxygen of the isatin fragment, the nitrogen atom of the azomethine group, and sulfur atom after deprotonation to give five membered rings. H1 NMR spectrum of the ligand shows only one set of signals for the aromatic protons, while the NH of isatin and NH of hydrazone give rise to two different singlets in the 11–14 ppm range. The formulations, [Cu(L)Cl]·2H2O, [Cu(L)(CH3COO)]·2H2O, [Ni(L)Cl], [Ni(L)(CH3COO)], [Co(L2)], and [Zn(L2)]·2H2O are in accordance with elemental analyses, physical, and spectroscopic measurements. The complexes are soluble in organic solvents. Molar conductance values in DMF indicate the nonelectrolytic nature of the complexes. Copper complex displays quasireversible cyclic voltametric responses with Ep near −0.659 v and 0.504 v Vs Ag/AgCl at the scan rate of 0.1 V/s. Copper(II) complexes show a single line EPR signals. For the observed magnetic moment and electronic spectral data possible explanation has been discussed. From all the available data, the probable structures for the complexes have been proposed. The compounds synthesized in present study have shown promising cytotoxic activity when screened using the in vitro method and at the same time were shown to have good activity when tested using the Ehrlich ascites carcinoma (EAC) model. The antimicrobial screening showed that the cobalt complex possesses enhanced antimicrobial activity towards fungi

Best chirplet chain: near-optimal detection of gravitational wave chirps

The list of putative sources of gravitational waves possibly detected by the ongoing worldwide network of large scale interferometers has been continuously growing in the last years. For some of them, the detection is made difficult by the lack of a complete information about the expected signal. We concentrate on the case where the expected GW is a quasi-periodic frequency modulated signal i.e., a chirp. In this article, we address the question of detecting an a priori unknown GW chirp. We introduce a general chirp model and claim that it includes all physically realistic GW chirps. We produce a finite grid of template waveforms which samples the resulting set of possible chirps. If we follow the classical approach (used for the detection of inspiralling binary chirps, for instance), we would build a bank of quadrature matched filters comparing the data to each of the templates of this grid. The detection would then be achieved by thresholding the output, the maximum giving the individual which best fits the data. In the present case, this exhaustive search is not tractable because of the very large number of templates in the grid. We show that the exhaustive search can be reformulated (using approximations) as a pattern search in the time-frequency plane. This motivates an approximate but feasible alternative solution which is clearly linked to the optimal one. [abridged version of the abstract]Comment: 23 pages, 9 figures. Accepted for publication in Phys. Rev D Some typos corrected and changes made according to referee's comment