95,042 research outputs found
New resonant behavior in the spin resolved photoionization of the rare gas atoms Kr 3d and Xe 4p
No full textKhalil T. New resonant behavior in the spin resolved photoionization of the rare gas atoms Kr 3d and Xe 4p. Bielefeld (Germany): Bielefeld University; 2002.In the first part of this thesis, the transferred spin polarization of resonantly excited Auger electrons of Kr 3d-1 5p photoionized by circularly polarized light was measured. The transferred spin polarization is related to the orientation A10 (and alignment A20) of core holes induced by the primary photoionization process, and to the intrinsic parameters [xi]1 which characterizes the transferred spin polarization of Auger electrons and [alpha]2, the anisotropy parameter which characterizes the angular intensity distribution of Auger electrons. Due to the selection rules of dipole excitation of Kr 3d-1 5p atoms i.e. Ji=1, A10 and A20 are known, [alpha]2 was calculated and measured by Kitajima et al. The calculation of [xi]1 was performed by N. M. Kabachnik and S. Fritzsche.
In the second part of this thesis, the spin polarization of Xe 4p near the ionization threshold was measured to examine the calculations of Cherepkov of contribution of the lowest order nondipole term; the electric-dipole-electric-quadrupole interference terms to the spin polarization of Xe np photoelectrons. The quadrupol matrix elements of the np->[epsilon]f transitions in Xe calculated in RPAE have strong maxima near the ionization threshold. This behaviour is similar to the well-known maxima in the dipole nd->[epsilon]f transitions. These dipole nd->[epsilon]f transitions are responsible for the so-called giant resonances in the total photoionization cross section. They are attributed to the double-well shape of the effective potential for the dipole [epsilon]f partial waves. Both the RPAE non-relativistic calculation from Cherepkov and the relativistic IPA adapted calculation from Derevianko agree qualitatively with the measured nondipole component of electron spin polarization
Atmospheric Methane Concentrations
No full textIt was first discovered that the atmospheric concentration of methane was increasing based upon samples collected in the late seventies and early eighties at Cape Meares, Oregon (Rasmussen and Khalil, 1981). Since that time, more detailed and extensive data sets have allowed estimation of sources and sinks of methane on the global scale. As attempts are made to refine these estimates, the value of the current databases will be greatly increased, as will the need for more current data
High-performance f-GO/MWCNTs-COOH nanohybrid-based polylactic acid mixed matrix membrane for wastewater treatment
No full textTo enhance the green polylactic acid (PLA) membrane's efficiency for removing organic materials, self-assembled functionalized graphene oxide carboxylic multi-walled carbon nanotubes (f-GO/MWCNTs-COOH) was incorporated into the membrane matrix followed by immersion precipitation. The successful formation of the negatively charged f-GO/MWCNTs-COOH nanohybrid was verified by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and zeta potential analyzer. The effect of different nanohybrid contents (1.5, 3 and 6 wt%) on the PLA membrane performance was investigated. The prepared mixed matrix membranes were analyzed by FT-IR, XRD, SEM, contact angle, porosity, and pore size analysis. Synthetic organic foulant bovine serum albumin (BSA), humic acid (HA) solutions were utilised to test the antifouling behaviour of membranes. In addition, raw wastewater from a wastewater treatment plant (WWTP) was used to further assess the performance of the membranes. The results indicated that with only 3 wt% f-GO/MWCNTs-COOH nanohybrid in the PLA membrane matrix, the fouling tendency was attenuated (superior rejection rates for BSA and HA of 96 % and 98 %, respectively.) and the pure water flux was increased to almost 80 L/m2hbar, compared to the neat PLA membrane (27 L/m2hbar), without compromising the high organic removal efficiency. According to the results of this study, the f-GO/MWCNTs-COOH nanohybrid has great potential to enhance the performance of mixed matrix membranes in raw wastewater treatment applications
Sustainable and green polylactic acid-based membrane embedded with self-assembled positively charged f-MWCNTs/GO nanohybrids for the removal of nutrients from wastewater
No full textIn this study, the synthesis, and chemical-physical characterization of self-assembled positively charged multi-walled carbon nanotubes/graphene oxide (f-MWCNTs)/(GO)-nanohybrids into adsorptive PLA-based membranes were investigated. The application of the innovative PLA/f-MWCNTs/GO membrane was investigated for the removal of nutrients such as nitrogen (N) and phosphorus (P) from both synthetic and real wastewater by performing various characterization and performance tests. The positively charged nanohybrid was prepared by electrostatic self-assembly of positively charged f-MWCNTs and negatively charged GO. The amount of nanohybrid loading in the nanocomposite membranes varied from 0 to 6 wt%, and its effects on nutrient removal and water flux were investigated. It is demonstrated that with the addition of only 1.5 wt% f-MWCNT/GO nanohybrid into the PLA matrix, the water flux increased by 74% when compared to the unmodified membrane. Also, up to 90.1 +/- 3.4% and 71.3 +/- 3.1% removal rates of ammonium-nitrogen (NH4+-N) and phosphate (PO43--P) ions were achieved using raw wastewater, respectively. The obtained results confirm the practical usability of the proposed innovative material for membrane fabrication in real wastewater treatment applications and can open doors to efficient and sustainable methods for nutrient removal
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Performance evaluation of trimethylamine–carbon dioxide thermolytic draw solution for engineered osmosis
No full textWe evaluated the performance of trimethylamine-carbon dioxide (TMA-CO2) as a potential thermolytic draw solution for engineered osmosis. Water flux and reverse solute flux with TMA-CO2 draw solution were measured in forward osmosis (FO) and pressure retarded osmosis (PRO) modes using thin-film composite (TFC) and cellulose triacetate (CTA) FO membranes. Water flux with the TMA-CO2 draw solution was comparable to that obtained with the more common ammonia-carbon dioxide (NH3-CO2) thermolytic draw solution at similar (1 M) concentration. Using a TFC-FO membrane, the water fluxes produced by 1 M TMA-CO2 and NH3-CO2 draw solutions with a DI water feed were, respectively, 33.4 and 35.6 L m(-2) h(-1) in PRO mode and 14.5 and 152 L m(-2) h(-1) in FO mode. Reverse draw permeation of TMA-CO2 was relatively low compared to NH3-CO2, ranging from 0.1 to 0.2 mol m(-2) h(-1) in all experiments, due to the larger molecular size of TMA. Thermal separation and recovery efficiency for TMA-CO2 was compared to NH3-CO2 by modeling low-temperature vacuum distillation utilizing low-grade heat sources. We also discuss possible challenges in the use TMA-CO2, including potential adverse impact on human health and environments. (C) 2014 Elsevier B.V. All rights reserved.
Contracts and productive information gathering
No full textWe modify a standard Baron-Myerson model by assuming that, instead of knowing the state of nature, the agent has to incur a cost, (g) , to learn it. Under these conditions, the principal will offer contracts that, depending on the value of (g), incite the agent to gather or not to gather information. We study tradeoffs that are involve
Numerical investigation of ALFRED under seismic scenario
No full textThe European project ANSELMUS focuses on the safety of advanced Heavy Liquid Metal (HLM) cooled reactors, including ALFRED, developed by the FALCON consortium, The reactor's operation progresses through three power levels (100, 200, and 300 MWth), requiring significant preliminary R&D efforts. The first ANSELMUS WP includes a Phenomena Identification Ranking Table (PIRT) analysis on ALFRED to prioritize R&D activities starting with ALFRED's reference design, selecting accidental transients to enhance the understanding of critical quantities known as FoMs (Figure of Merits). Supporting numerical analyses are
executed within the same project. This paper examines core compaction following a seismic scenario using a detailed nodalization developed with the RELAP5 system code
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