7,984 research outputs found
iObjectify: self- and other-objectification on Grindr, a geosocial networking application designed for men who have sex with men
Grindr is a smartphone application for men who have sex with men (MSM). Despite its reputation as a ‘hook-up app’, little is known about its users’ self-presentation strategies and how this relates to objectification - this paper explores objectification on Grindr. The results of Study 1 showed that Grindr users objectified other men more than non-Grindr users. A content analysis of 1400 Grindr profiles in Study 2 showed that profile pictures with objectifying content were related to searching for sexual encounters. Finally, a survey of Grindr users in Study 3 revealed that objectification processes and sexualized profile pictures were related to some objectification-relevant online behaviors (e.g., increased use of Grindr, discussion of HIV status). Interestingly, the presence of body focused profile content was more related to sexual orientation disclosure (not being ‘out’) than to objectification. This paper presents evidence that Grindr usage and online presentation are related to objectification processes
Impedance Characterization of a Model Au/Yttria-Stabilized Zirconia/Au Electrochemical Cell in Varying Oxygen and NO\u3csub\u3e\u3cem\u3ex\u3c/em\u3e\u3c/sub\u3e Concentrations
An electrochemical cell [Au/yttria-stabilized zirconia (YSZ)/Au] serves as a model system to investigate the effect of O2 and NOx. Possible mechanisms responsible for the response are presented. Two dense Au electrodes are co-located on the same side of a dense YSZ electrolyte and are separated from the electrolyte by a porous YSZ layer, present only under the electrodes. While not completely understood, the porous layer appears to result in enhanced NOx response. Impedance data were obtained over a range of frequencies 0.1 Hz to 1 MHz, temperatures 600–700°C, and oxygen 2–18.9% and NOx 10–100 ppm concentrations. Spectra were fit with an equivalent circuit, and values of the circuit elements were evaluated. In the absence of NOx, the effect of O2 on the low-frequency arc resistance could be described by a power law, and the temperature dependence by a single apparent activation energy at all O2 concentrations. When both O2 and NOx were present, however, the power-law exponent varied as a function of both temperature and concentration, and the apparent activation energy also showed dual dependence. Adsorption mechanisms are discussed as possibilities for the rate-limiting steps. Implications for impedancemetric NOx sensing are also discussed
Optical conductivity in the normal state fullerene superconductors
We calculate the optical conductivity, , in the normal state
fullerene superconductors by self-consistently including the impurity
scatterings, the electron-phonon and electron-electron Coulomb interactions.
The finite bandwidth of the fullerenes is explicitely considered, and the
vertex corection is included Nambu in calculating the renormalized
Green's function. is obtained by calculating the
current-current correlation function with the renormalized Green's function in
the Matsubara frequency and then performing analytic continuation to the real
frequency at finite temperature. The Drude weight in is
strongly suppressed due to the interactions and transfered to the mid-infrared
region around and above 0.06 eV which is somewhat less pronounced and much
broader compared with the expermental observation by DeGiorgi .Comment: 6 pages, 4 figures. To be published in Physical Review B, July 1
Predicting ocean-induced ice-shelf melt rates using deep learning
Through their role in buttressing upstream ice flow, Antarctic ice shelves play an important part in regulating future sea-level change. Reduction in ice-shelf buttressing caused by increased ocean-induced melt along their undersides is now understood to be one of the key drivers of ice loss from the Antarctic ice sheet. However, despite the importance of this forcing mechanism, most ice-sheet simulations currently rely on simple melt parameterisations of this ocean-driven process since a fully coupled ice–ocean modelling framework is prohibitively computationally expensive. Here, we provide an alternative approach that is able to capture the greatly improved physical description of this process provided by large-scale ocean-circulation models over currently employed melt parameterisations but with trivial computational expense. This new method brings together deep learning and physical modelling to develop a deep neural network framework, MELTNET, that can emulate ocean model predictions of sub-ice-shelf melt rates. We train MELTNET on synthetic geometries, using the NEMO ocean model as a ground truth in lieu of observations to provide melt rates both for training and for evaluation of the performance of the trained network. We show that MELTNET can accurately predict melt rates for a wide range of complex synthetic geometries, with a normalised root mean squared error of 0.11 m yr−1 compared to the ocean model. MELTNET calculates melt rates several orders of magnitude faster than the ocean model and outperforms more traditional parameterisations for > 96 % of geometries tested. Furthermore, we find MELTNET's melt rate estimates show sensitivity to established physical relationships such as changes in thermal forcing and ice-shelf slope. This study demonstrates the potential for a deep learning framework to calculate melt rates with almost no computational expense, which could in the future be used in conjunction with an ice sheet model to provide predictions for large-scale ice sheet models.</p
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Impedancemetric Technique for NOx Sensing Using a YSZ-Based Electrochemical Cell
An impedancemetric technique for NO{sub x} sensing using a yttria-stabilized zirconia (YSZ) electrochemical cell is reported. The cell consists of a dense YSZ substrate disk with two YSZ/metal-oxide electrodes deposited on the same side. The cell is completely exposed to the test gas (no air reference). The NO{sub x} and O{sub 2} response of the cell were evaluated during constant-frequency operation at frequencies in the range from 1 to 1000 Hz. At 10 Hz, the NO{sub x} response (as measured by phase angle shift) is shown to be linear with concentration over the range from 8-50 ppm, with comparable response to both NO and NO{sub 2}. A method of operation is described which enables compensation for the O{sub 2} response at oxygen concentrations greater than approximately 4%. This mode of operation allows the sensor to provide sub-10 ppm detection of NO{sub x} irrespective of the O{sub 2} concentration. The sensor exhibits good stability during continuous operation for more than 150 hr. It was observed that the O{sub 2} response of the cell is too slow to be of practical use, taking several minutes to equilibrate after changing the concentration by a few percent. However, data will be presented which demonstrate that this response is related to the metal oxide used for the electrode; and more rapid response times can be achieved by modification of the electrode material
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Impedancemetric NOx Sensing Using Yttria-Stabilized Zirconia (YSZ) Electrolyte and YSZ/Cr2O3 Composite Electrodes
An impedancemetric method for NO{sub x} sensing using an yttria-stabilized zirconia (YSZ) based electrochemical cell is described. The sensor cell consists of a planar YSZ electrolyte and two identical YSZ/Cr{sub 2}O{sub 3} composite electrodes exposed to the test gas. The sensor response to a sinusoidal ac signal applied between the two electrodes is measured via two parameters calculated from the complex impedance, the modulus |Z| and phase angle {Theta}. While either of these parameters can be correlated to the NO{sub x} concentration in the test gas, {Theta} was found to provide a more robust metric than |Z|. At frequencies below approximately 100 Hz, {Theta} is sensitive to both the NO{sub x} and O{sub 2} concentrations. At higher frequencies, {Theta} is predominantly affected by the O{sub 2} concentration. A dual frequency measurement is demonstrated to compensate for changes in the O{sub 2} background between 2 and 18.9%. Excellent sensor performance is obtained for NO{sub x} concentrations in the range of 8-50 ppm in background. An equivalent circuit model was used to extract fitting parameters from the impedance spectra for a preliminary analysis of NO{sub x} sensing mechanisms
Dynamic Changes in LSM Nanoparticles on YSZ: A Model System for Non-Stationary SOFC Cathode Behavior
The interaction between nanoparticles of strontium-doped lanthanum manganite (LSM) and single-crystal yttria-stabilized zirconia (YSZ) was investigated using atomic force microscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX). Nanoparticles of LSM were deposited directly onto single-crystal YSZ (100) substrates using an ultrasonic spray nozzle. As samples were annealed from 850 to 1250 degrees C, nanoparticles gradually decreased in height and eventually disappeared completely. Subsequent reduction in H-2/H2O at 700 degrees C resulted in the reappearance of nanoparticles. Studies were carried out on identical regions of the sample, allowing the same nanoparticles to be characterized at different temperatures. Morphological changes indicate the formation of a thin layer of LSM, and XPS results support the observation by indicating an increase in signal from the La and Sr and a decrease in signal from the Y and Zr with increasing temperature. SEM/EDX was used to verify that the nanoparticles in the reduced sample contained La. The changes in the LSM/YSZ morphology may be important in explaining the nonstationary behavior observed in operating solid-oxide fuel cells (SOFCs). The thin layer of LSM initially results in poor cathode performance; reducing conditions then lead to film disruptions, indicating nano/microporosity, that increase oxygen ion diffusion and performance
Assessing the removal of organic micro-pollutants from anaerobic membrane bioreactor effluent by fertilizer-drawn forward osmosis
© 2017 Elsevier B.V. In this study, the behavior of organic micro-pollutants (OMPs) transport including membrane fouling was assessed in fertilizer-drawn forward osmosis (FDFO) during treatment of the anaerobic membrane bioreactor (AnMBR) effluent. The flux decline was negligible when the FO membrane was oriented with active layer facing feed solution (AL-FS) while severe flux decline was observed with active layer facing draw solution (AL-DS) with di-ammonium phosphate (DAP) fertilizer as DS due to struvite scaling inside the membrane support layer. DAP DS however exhibited the lowest OMPs forward flux or higher OMPs rejection rate compared to other two fertilizers (i.e., mono-ammonium phosphate (MAP) and KCl). MAP and KCl fertilizer DS had higher water fluxes that induced higher external concentration polarization (ECP) and enhanced OMPs flux through the FO membrane. Under the AL-DS mode of membrane orientation, OMPs transport was further increased with MAP and KCl as DS due to enhanced concentrative internal concentration polarization while with DAP the internal scaling enhanced mass transfer resistance thereby lowering OMPs flux. Physical or hydraulic cleaning could successfully recover water flux for FO membranes operated under the AL-FS mode but only partial flux recovery was observed for membranes operated under AL-DS mode because of internal scaling and fouling in the support layer. Osmotic backwashing could however significantly improve the cleaning efficiency
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