1,478 research outputs found

    Semiconductor grade, solar silicon purification project

    Get PDF
    The conversion of metallurgical grade silicon into semiconductor grade silicon by way of a three step SiF2 polymer transport purification process was investigated. Developments in the following areas were also examined: (1) spectroscopic analysis and characterization of (SiF2) sub x polymer and Si sub x F sub y homologue conversion; (2) demonstration runs on the near continuous apparatus; (3) economic analysis; and (4) elemental analysis

    Login History and CaRP for User Authentication

    Get PDF
    Password is main vulnerability in computer security. Passwords are commonly guessed by machine programs running dictionary attacks. Passwords main used for the authentication method in spite of security weaknesses. User authentication obviously practical issue. According to the view of a service provider this problem needs to be resolved within real-world constraints such as the available hardware and software infrastructures. According to user’s view user friendliness is a basic requirement Click based graphical password scheme provides a different approach to address the familiar image hotspot problem. Graphical password systems such as PassPoints, that frequently leads to weak password choices. So to provide user friend-liness and also the protection from various security attacks. In this, graphical password scheme, the click event is performed on various points on same or different images. DOI: 10.17762/ijritcc2321-8169.15064

    A Novel method for user authentication by CaRP And Login History

    Get PDF
    Cyber security is the main challenge nowadays. Many authentication techniques are available for these, for unwanted access for more secure data is prohibited. Graphical and text password are used for user authentication process. Sometimes text passwords are not secured and graphical password are more secure but vulnerable to shoulders surfing attack. The click event on various points for user friend-lines and protection from various security attacks. In system, login history image file combined CaRP for user authentication to enhancing the more security level primitives .The image file contain details of login and logout for date, time all related information. The file is encrypted by DES algorithm and send that file on mail. It is higher security primitives for the user. online guessing attack, relay attacks and if combined with dual technology for shoulder surfing attack are new concepts are available. DOI: 10.17762/ijritcc2321-8169.15075

    Doping dependence of the coupling of electrons to bosonic modes in the single-layer high-temperature Bi2Sr2CuO6 superconductor

    Get PDF
    A recent highlight in the study of high-Tc superconductors is the observation of band renormalization / self-energy effects on the quasiparticles. This is seen in the form of kinks in the quasiparticle dispersions as measured by photoemission and interpreted as signatures of collective bosonic modes coupling to the electrons. Here we compare for the first time the self-energies in an optimally doped and strongly overdoped, non-superconducting single-layer Bi-cuprate (Bi2Sr2CuO6). Besides the appearance of a strong overall weakening, we also find that weight of the self-energy in the overdoped system shifts to higher energies. We present evidence that this is related to a change in the coupling to c-axis phonons due to the rapid change of the c-axis screening in this doping range.Comment: 4 pages, 3 figure

    Application of the Beer–Lambert Model to Attenuation of Photosynthetically Active Radiation in a Shallow, Eutrophic Lake

    Full text link
    Models of primary production in aquatic systems must include a means to estimate subsurface light. Such models often use the Beer–Lambert law, assuming exponential attenuation of light with depth. It is further assumed that the diffuse attenuation coefficient may be estimated as a summation of scattering/absorbing constituent concentrations multiplied by their respective specific attenuation coefficients. While theoretical deviations from these assumptions have been documented, it is useful to consider the empirical performance of this common approach. Photosynthetically active radiation (PAR) levels and water quality conditions were recorded weekly from six to eight monitoring stations in western Lake Erie between 2012 and 2016. Exponential PAR extinction models yielded a mean attenuation coefficient of 1.55 m (interquartile range = 0.74–1.90 m). While more complex light attenuation models are available, analysis of residuals indicated that the simple Beer–Lambert model is adequate for shallow, eutrophic waters similar to western Lake Erie (R2 > 0.9 for 96% of samples). Three groups of water quality variables were predictive of PAR attenuation: total and nonvolatile suspended particles, dissolved organic substances (dissolved organic carbon and chromophoric dissolved organic matter), and organic solids (volatile suspended solids and chlorophyll). Multiple regression models using these variables predicted 3–90% of the variability in PAR attenuation, with a median adjusted R2 = 0.86. Explanatory variables within these groups may substitute for each other while maintaining similar model performance, indicating that various combinations of water quality variables may be useful to predict PAR attenuation, depending on availability within a model framework or monitoring program.Key PointsThe Beer–Lambert law effectively models photosynthetically active radiation in western Lake Erie, despite some systematic deviationsField‐obtained water quality parameters can predict photosynthetically active radiation attenuation with a high degree of confidenceSuspended particle concentration is most predictive of photosynthetically active radiation attenuation in this turbid, eutrophic basinPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/1/wrcr23654_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/2/wrcr23654-sup-0001-2018WR023024-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/3/wrcr23654.pd

    Coupling Of The B1g Phonon To The Anti-Nodal Electronic States of Bi2Sr2Ca0.92Y0.08Cu2O(8+delta)

    Full text link
    Angle-resolved photoemission spectroscopy (ARPES) on optimally doped Bi2Sr2Ca0.92Y0.08Cu2O(8+delta) uncovers a coupling of the electronic bands to a 40 meV mode in an extended k-space region away from the nodal direction, leading to a new interpretation of the strong renormalization of the electronic structure seen in Bi2212. Phenomenological agreements with neutron and Raman experiments suggest that this mode is the B1g oxygen bond-buckling phonon. A theoretical calculation based on this assignment reproduces the electronic renormalization seen in the data.Comment: 4 Pages, 4 Figures Updated Figures and Tex
    corecore