Carbon nanotubes immersed in superfluid helium: the Impact of quantum confinement on wetting and capillary action

7 págs.; 5 figs.; 1 tab. ; Associated content mp4 video: http://pubs.acs.org/doi/suppl/10.1021/acs.jpclett.6b02414A recent experimental study [Ohba, Sci. Rep. 2016, 6, 28992] of gas adsorption on single-walled carbon nanotubes at temperatures between 2 and 5 K reported a quenched propagation of helium through carbon nanotubes with diameters below 7 Å despite the small kinetic diameter of helium atoms. After assessing the performance of a potential model for the He−nanotube interaction via ab initio calculations with density functional theorybased symmetry adapted perturbation theory, we apply orbital-free helium density functional theory to show that the counterintuitive experimental result is a consequence of the exceptionally high zeropoint energy of helium and its tendency to form spatially separated layers of helium upon adsorption at the lowest temperatures. Helium filling factors are derived for a series of carbon nanotubes and compared to the available experimental data. © 2016 American Chemical SocietyThis work has been supported by the COST Action CM1405 “Molecules in Motion (MOLIM)”. M.P.d.L.-C. gratefully acknowledges support from MINECO (Spain) under Grant MAT2016-75354-P and thanks the CTI (CSIC) and CESGA supercomputer facilities (Spain) for the resources provided.Peer reviewe

Tuning bad metal and non-Fermi liquid behavior in a Mott material: rare earth nickelate thin films

Resistances that exceed the Mott-Ioffe-Regel limit, known as bad metal behavior, and non-Fermi liquid behavior are ubiquitous features of the normal state of many strongly correlated materials. Here we establish the conditions that lead to bad metal and non-Fermi liquid phases in NdNiO3, which exhibits a prototype, bandwidth-controlled metal-insulator transition. We show that resistance saturation is determined by the magnitude of the Ni eg orbital splitting, which can be tuned by strain in epitaxial films, causing the appearance of bad metal behavior under certain conditions. The results shed light on the nature of a crossover to non-Fermi liquid metal phase and provide a predictive criterion for strong localization. They elucidate a seemingly complex phase behavior as a function of film strain and confinement and provide guidelines for orbital engineering and novel devices.Comment: Manuscript text, 5 figures and supplemen

Growth and Malnutrition in Ethiopia

This article focuses on anthropometric parameters as height for age, weight for age and weight for height, which are among the most used tools for assessing well-being of infants and children. Such data have been collected between 1992–1993 from samples of infants and children aged between 2 and 10 years from urban and rural areas of Ethiopia. Similar to many other reports from developing countries the great amount of malnourished children is preoccupying as reflected by about 15% of children below the 5th centile of weight for height and about 53% of children below the 5th centile of height for age and about 45% below the 5th centile of weight for age

Multiple sclerosis susceptibility alleles in African Americans.

Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by complex genetics and multifaceted gene-environment interactions. Compared to whites, African Americans have a lower risk for developing MS, but African Americans with MS have a greater risk of disability. These differences between African Americans and whites may represent differences in genetic susceptibility and/or environmental factors. SNPs from 12 candidate genes have recently been identified and validated with MS risk in white populations. We performed a replication study using 918 cases and 656 unrelated controls to test whether these candidate genes are also associated with MS risk in African Americans. CD6, CLEC16a, EVI5, GPC5, and TYK2 contained SNPs that are associated with MS risk in the African American data set. EVI5 showed the strongest association outside the major histocompatibility complex (rs10735781, OR=1.233, 95% CI=1.06-1.43, P-value=0.006). In addition, RGS1 seems to affect age of onset whereas TNFRSF1A seems to be associated with disease progression. None of the tested variants showed results that were statistically inconsistent with the effects established in whites. The results are consistent with shared disease genetic mechanisms among individuals of European and African ancestry

Ball on a beam: stabilization under saturated input control with large basin of attraction

This article is devoted to the stabilization of two underactuated planar systems, the well-known straight beam-and-ball system and an original circular beam-and-ball system. The feedback control for each system is designed, using the Jordan form of its model, linearized near the unstable equilibrium. The limits on the voltage, fed to the motor, are taken into account explicitly. The straight beam-and-ball system has one unstable mode in the motion near the equilibrium point. The proposed control law ensures that the basin of attraction coincides with the controllability domain. The circular beam-and-ball system has two unstable modes near the equilibrium point. Therefore, this device, never considered in the past, is much more difficult to control than the straight beam-and-ball system. The main contribution is to propose a simple new control law, which ensures by adjusting its gain parameters that the basin of attraction arbitrarily can approach the controllability domain for the linear case. For both nonlinear systems, simulation results are presented to illustrate the efficiency of the designed nonlinear control laws and to determine the basin of attraction

Effect of spin orbit scattering on the magnetic and superconducting properties of nearly ferromagnetic metals: application to granular Pt

We calculate the effect of scattering on the static, exchange enhanced, spin susceptibility and show that in particular spin orbit scattering leads to a reduction of the giant moments and spin glass freezing temperature due to dilute magnetic impurities. The harmful spin fluctuation contribution to the intra-grain pairing interaction is strongly reduced opening the way for BCS superconductivity. We are thus able to explain the superconducting and magnetic properties recently observed in granular Pt as due to scattering effects in single small grains.Comment: 9 pages 3 figures, accepted for publication in Phys. Rev. Letter

Application of SINTACS method to the aquifers of Piana di Palermo, Siciliy,Italy

Piana di Palermo is characterized by the presence of two different aquifers: one shallow, constituted by calcarenites and the other deep in fractured carbonates. The calcarenitic aquifer presents a low potential compared to the carbonatic aquifer. The chemistry of the water in both aquifers reflects water-rock interaction, seawater intrusion, ionic exchange etc. The application of SINTACS method showed that about 80% of the study area can be classified as of high to very high vulnerability.Piana di Palermo es caracterizada por la presencia de dos acuíferos diferentes: uno somero constituido por calcarenitas y otro profundo en rocas carbonatadas fracturadas. El acuífero calcarenítico presenta un bajo potencial hídrico comparado con el acuífero carbonático. El comportamiento químico del agua en ambos acuíferos refleja severos procesos como interacción agua-roca, intrusión marina, cambio iónico, etc. La aplicación del método SINTACS mostró que cerca del 80 % del área en estudio puede ser clasificada como de alta a muy alta vulnerabilidad

Excavaciones de Numancia : memoria presentada al Ministerio de Instrucción Pública y Bellas Artes por la Comisión Ejecutiva

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201