3,611 research outputs found

    Tunnel Spin Polarization Versus Energy for Clean and Doped Al2O3 Barriers

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    The variation of the tunnel spin-polarization (TSP) with energy is determined using a magnetic tunnel transistor, allowing quantification of the energy dependent TSP separately for both ferromagnet/insulator interfaces and direct correlation with the tunnel magnetoresistance (TMR) measured in the same device. The intrinsic TSP is reduced below the Fermi level, and more strongly so for tunneling into empty states above the Fermi level. For artificially doped barriers, the low bias TMR decreases due to defect-assisted tunneling. Yet, this mechanism becomes ineffective at large bias, where instead inelastic spin scattering causes a strong TMR decay

    Tunnel spin polarization of Ni80Fe20/SiO2 probed with a magnetic tunnel transistor

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    The tunnel spin polarization of Ni80Fe20/SiO2 interfaces has been investigated using a magnetic tunnel transistor (MTT). The MTT with a Ni80Fe20/SiO2 emitter shows a magnetocurrent of 74% at 100 K, corresponding to a tunnel spin polarization of the Ni80Fe20/SiO2 interface of 27%. This is only slightly lower than the value of 34% for Ni80Fe20/Al2O3 interfaces determined in similar MTT structures. This suggests that SiO2 can be applied in semiconductor spintronic devices, for example in ferromagnet/SiO2/Si tunnel contacts for spin injection.\ud \u

    Opposite Spin Asymmetry of Elastic and Inelastic Scattering of Nonequilibrium Holes Injected into a Ferromagnet

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    The spin asymmetry of elastic and inelastic scattering of nonequilibrium holes injected into Co thin films is examined using a p-type magnetic tunnel transistor. Spin-dependent transmission yields a positive or negative magnetocurrent depending on Co thickness and hole energy. Up to a critical thickness of about 3 nm, (quasi)elastic scattering dominates with a short attenuation length (<1 nm) and preferential attenuation of holes in the majority spin bands, consistent with spin-wave emission. At a larger Co thickness, inelastic scattering dominates with a larger attenuation length (~4 nm) and opposite spin asymmetry

    CFD Simulation of Liquid-solid Multiphase Flow in Mud Mixer

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    In the present study, a computational fluid dynamics (CFD) simulation was performed to analyze the mixing phenomena associated with multi-phase flow in a mud mixing system. For the validation of CFD simulation, firstly a liquid-solid multiphase flow inside horizontal pipe was simulated and compared with the experiments and other numerical simulations. And then, the multiphase flow simulation was carried out for the mud mixer in the drilling handling system in order to understand mixing phenomena and predict the mixing efficiency. For the modeling and simulation, a commercial software, STAR-CCM+, based on a finite-volume method (FVM) was adopted. The simulation results for liquid-solid flow inside the pipe shows a good agreement with the experimental data. With the same multiphase model, the simulation for mud mixer is performed under the generalized boundary condition and then pressure drop through the mud mixer will be discussed

    Reflections in the Mirror: Women’s Self Comparisons to Mannequins and Peers

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    The fashion industry has been under fire for years for using unrealistic body sizes in the form of stick-thin fashion models to promote the sale of clothing. Typical Western fashion models in today’s society are sized 0-2 and weigh approximately 23% less than the average U.S. woman, who weighs approximately 163 pounds and wears a size 14 (Vesilind, 2009). According to Vartanian (2009), many women suffer from body image self-discrepancies when they compare themselves with others, including fashion models. As such, social comparison has been documented to create negative emotions, such as body dissatisfaction and disappointment (Posavac & Posavac, 2002). Although a number of studies have investigated how an idealized body image in media impacts social comparison among females, no research has explored to what extent comparisons of mannequins to a customer’s self may impact self-image and consumer behavior. Since mannequins serve to show consumers how clothing may look on the human body and consumers may be drawn to the clothing due to the way the clothing fits the mannequin and/or the poise, stature, or grace of the mannequin itself (Schneider, 1997), it should be expected that mannequins would also influence self-image and behavior. Utilizing Social Comparison Theory as the theoretical foundation, this study examines the influencing factors affecting U.S. females\u27 social comparison tendencies and psychological well-being when a female compares her body to that of a mannequin and to other women. Data was collected using an online survey through the use of snowball convenience sampling, yielding 314 usable responses. Results indicate that the use of idealized mannequins in retail stores have a significant impact on social comparison and body dissatisfaction for female consumers. These results suggest that female consumers do indeed compare their bodies to those of mannequins and that the greater the discrepancy between the size of the mannequin and their own size, the more dissatisfied the woman is with her body. This research extends Social Comparison Theory as the findings show women also compare themselves to mannequins. In addition, results of this study show that women who are categorized with a BMI classification of overweight or obese are more likely to compare themselves to other females. Results also show that the top five body parts/characteristics most commonly compared to mannequins and other females are body size, weight, body shape, waist, and legs

    Fine control of carbon nanotubes-polyelectrolyte sensors sensitivity by electrostatic layer by layer assembly (eLbL) for the detection of volatile organic compounds (VOC)

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    International audienceVolatile organic compounds (VOC) sensors have recently extended their field of application to medical area as they are considered as biomarkers in anticipated diagnosis of diseases such as lung cancer by breath analysis. Conductive polymer nanocomposites (CPC) have already proved their interest to fabricate sensors for the design of electronic noses (e-noses) but, for the first time to our knowledge, the present study is showing that electrostatic layer by layer assembly (eLbL) is bringing an interesting input to tailor the sensitivity of carbon nanotubes (CNT)-polyelectrolyte sensors. By this technique transducers are progressively built in 3D alternating dipping into sodium deoxycholate (DOC)-stabilized SWNT and poly(diallyldimethyl-ammonium chloride) [PDDA] solutions, respectively anionic and cationic. The precise control of transducers thicknesses (between 5 and 40 nm) resulting from this process allows a fine tuning of multilayer films resistance (between 50 and 2 kΩ) and thus of their sensitivity to VOC. Interestingly the surfactant used to disperse CNT into water, DOC is also found to enhance CNT sensitivity to vapors so is it for the polyelectrolyte PDDA. Finally it is found that transducers with 16 bilayers of PDDA/DOC-CNT provide optimum chemo-resistive properties for the detection and discrimination of the eight vapors studied (chloroform, acetone, ethanol, water, toluene, dichloromethane, tetrahydrofuran and methanol)

    Intrinsic decoherence and classical-quantum correspondence in two coupled delta-kicked rotors

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    We show that classical-quantum correspondence of center of mass motion in two coupled delta-kicked rotors can be obtained from intrinsic decoherence of the system itself which occurs due to the entanglement of the center of mass motion to the internal degree of freedom without coupling to external environment

    Effects of various additives to enhance growth performance, blood profiles, and reduce malodour emissions in growing pigs

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    Experiment 1 was a feeding trial in which 75 (Landrace ⅹ Yorkshire) ⅹ Duroc pigs with average initial bodyweight (BW) of 26 ± 1 kg were used. It was assigned to three pigs/pen and five pens/treatment. Experiment 2 was a metabolic trial in which 25 (LandraceⅹYorkshire)ⅹDuroc pigs with average initial bodyweight (BW) of 36 ± 1 kg were used. The basal diet consisted of maize (57.71 %), soybean meal (32.45 %), and wheat bran (5 %). Treatments consisted of i) CON (control diet); ii) OE (organic acid + essential oils) (Aviplus-S®), that is, CON + 0.05 % OE; iii) OC (organic charcoal) (Olga Black®), that is, CON + 0.1 % OC; iv) AE (anise extracts) (RESQ®), that is, CON + 0.015 % AE; and v) PB (probiotics) (Bonvital®), that is, CON + 0.1 % PB. Average daily gain (ADG) and gain/feed ratio (G : F) were significantly higher in the OE and AE groups than in the others. Average daily feed intake (ADFI) for OE, OC, and AE treatments was significantly higher than that for CON and PB treatments. Dry matter (DM) digestibility was significantly higher in AE than CON. Crude protein (CP) was significantly higher in OE, AE, and PB than CON. CON and other treatments did not cause significant differences in blood l-density lipoprotein (LDL), and glucose. NH3 emissions were significantly lower in all treated groups than in CON. Among the treatments, NH3 emissions were lowest in OE and AE. H2S emissions were significantly lower in OE, AE, and PB than in CON. Among the treatments, OE and AE were most effective at reducing H2S emissions. The emissions of volatile fatty acids (VFAs) showed no significant difference between treatments and CON. In conclusion, this experiment was shown to be more effective on growth performance, malodour emission, blood profiles, and nutrient digestibility in OE and AE than other additives.Keywords: Digestibility, feed, influence, odour, supplementation, swin

    Z boson pair production at LHC in a stabilized Randall-Sundrum scenario

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    We study the Z boson pair production at LHC in the Randall-Sundrum scenario with the Goldberger-Wise stabilization mechanism. It is shown that comprehensive account of the Kaluza-Klein graviton and radion effects is crucial to probe the model: The KK graviton effects enhance the cross section of gg→ZZg g \to Z Z on the whole so that the resonance peak of the radion becomes easy to detect, whereas the RS effects on the qqˉ→ZZq\bar{q} \to Z Z process are rather insignificant. The pTp_T and invariant-mass distributions are presented to study the dependence of the RS model parameters. The production of longitudinally polarized Z bosons, to which the SM contributions are suppressed, is mainly due to KK gravitons and the radion, providing one of the most robust methods to signal the RS effects. The 1σ1 \sigma sensitivity bounds on (Λπ,mϕ)(\Lambda_\pi, m_\phi) with k/MPl=0.1k/M_{\rm Pl} =0.1 are also obtained such that the effective weak scale Λπ\Lambda_\pi of order 5 TeV can be experimentally probed.Comment: 28 pages, LaTex file, 18 eps figure
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