Terahertz Sieves

[EN] Imaging at terahertz (THz) frequencies offers a great potential for applications including security screening, telecommunications biodetection, and spectroscopy. Some of these applications need specially designed lenses with customized characteristics that are not commercially available. In this letter, we present the THz sieves as a new kind of THz lenses. We demonstrate that these lenses improve the resolution of conventional zone plates constructed with the same level of detail. Amplitude and phase THz sieves were three-dimensional printed and tested experimentally. Excellent agreement was obtained between the experimental and calculated results.This work was supported in part by the Ministerio de Economia y Competitividad and FEDER, Spain, under Grant DPI2015-71256-R, in part by the Generalitat Valenciana under Grant PROMETEOII-2014-072, Spain, and in part by the National Center for Research and Development in Poland under Grant LIDER/020/319/L-5/13/NCBR/2014.Machado-Olivares, FJ.; Zagrajek, P.; Monsoriu Serra, JA.; Furlan, WD. (2018). Terahertz Sieves. IEEE Transactions on Terahertz Science and Technology. 8(1):140-143. https://doi.org/10.1109/TTHZ.2017.2762292S1401438

Would You Be Happier If You Looked Better? A Focusing Illusion

Some people might believe that individuals who are more satisfied with their body are also happier. However, people tend to overrate the influence of some factors (e.g. money or health) on their happiness; a phenomenon termed the focusing illusion. Our aim was to examine the focusing illusion in relation to body satisfaction. We experimentally manipulated body satisfaction and life satisfaction focus by varying the order of relevant measurement scales. Volunteers (N = 97) completed two questionnaires placed in separate envelopes to control the order of scales administration. Participants either completed the Body Satisfaction Scale followed by the Satisfaction with Life Scale or vice versa. In line with the focusing illusion the association between body satisfaction and life satisfaction was significantly stronger when participants were asked about their body satisfaction first. Body satisfaction as a focusing illusion may need to be considered by scientist as well as lay people who try to look better and be happier

Feasibility of Undertaking Off-Site Infant Eye-Tracking Assessments of Neuro-Cognitive Functioning in Early-Intervention Centres

Recent work suggests that differences in functional brain development are already identifiable in 6- to 9-month-old infants from low socio-economic status (SES) backgrounds. Investigation of early SES-related differences in neuro-cognitive functioning requires the recruitment of large and diverse samples of infants, yet it is often difficult to persuade low-SES parents to come to a university setting. One solution is to recruit infants through early intervention children’s centres (CCs). These are often located in areas of high relative deprivation to support young children. Given the increasing portability of eye-tracking equipment, assessment of large clusters of infants could be undertaken in centres by suitably trained early intervention staff. Here, we report on a study involving 174 infants and their parents, carried out in partnership with CCs, exploring the feasibility of this approach. We report the processes of setting up the project and participant recruitment. We report the diversity of sample obtained on the engagement of CC staff in training and the process of assessment itself.We report the quality of the data obtained, and the levels of engagement of parents and infants. We conclude that this approach has great potential for recruiting large and diverse samples worldwide, provides sufficiently reliable data and is engaging to staff, parents and infants

Cataclysmic Variables in the First Year of the Zwicky Transient Facility

Using selection criteria based on amplitude, time, and color, we have identified 329 objects as known or candidate cataclysmic variables (CVs) during the first year of testing and operation of the Zwicky Transient Facility. Of these, 90 are previously confirmed CVs, 218 are strong candidates based on the shape and color of their light curves obtained during 3–562 days of observation, and the remaining 21 are possible CVs but with too few data points to be listed as good candidates. Almost half of the strong candidates are within 10 deg of the galactic plane, in contrast to most other large surveys that have avoided crowded fields. The available Gaia parallaxes are consistent with sampling the low mass transfer CVs, as predicted by population models. Our follow-up spectra have confirmed Balmer/helium emission lines in 27 objects, with four showing high-excitation He ii emission, including candidates for an AM CVn, a polar, and an intermediate polar. Our results demonstrate that a complete survey of the Galactic plane is needed to accomplish an accurate determination of the number of CVs existing in the Milky Way

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski, Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy), Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy

Cataclysmic Variables in the First Year of the Zwicky Transient Facility

Using selection criteria based on amplitude, time, and color, we have identified 329 objects as known or candidate cataclysmic variables (CVs) during the first year of testing and operation of the Zwicky Transient Facility. Of these, 90 are previously confirmed CVs, 218 are strong candidates based on the shape and color of their light curves obtained during 3–562 days of observation, and the remaining 21 are possible CVs but with too few data points to be listed as good candidates. Almost half of the strong candidates are within 10 deg of the galactic plane, in contrast to most other large surveys that have avoided crowded fields. The available Gaia parallaxes are consistent with sampling the low mass transfer CVs, as predicted by population models. Our follow-up spectra have confirmed Balmer/helium emission lines in 27 objects, with four showing high-excitation He ii emission, including candidates for an AM CVn, a polar, and an intermediate polar. Our results demonstrate that a complete survey of the Galactic plane is needed to accomplish an accurate determination of the number of CVs existing in the Milky Way

Social features of online networks: the strength of intermediary ties in online social media

An increasing fraction of today social interactions occur using online social media as communication channels. Recent worldwide events, such as social movements in Spain or revolts in the Middle East, highlight their capacity to boost people coordination. Online networks display in general a rich internal structure where users can choose among different types and intensity of interactions. Despite of this, there are still open questions regarding the social value of online interactions. For example, the existence of users with millions of online friends sheds doubts on the relevance of these relations. In this work, we focus on Twitter, one of the most popular online social networks, and find that the network formed by the basic type of connections is organized in groups. The activity of the users conforms to the landscape determined by such groups. Furthermore, Twitter's distinction between different types of interactions allows us to establish a parallelism between online and offline social networks: personal interactions are more likely to occur on internal links to the groups (the weakness of strong ties), events transmitting new information go preferentially through links connecting different groups (the strength of weak ties) or even more through links connecting to users belonging to several groups that act as brokers (the strength of intermediary ties).Comment: 14 pages, 18 figure

Spin transition of Fe 3+ in Al-bearing phase D: An alternative explanation for small-scale seismic scatterers in the mid-lower mantle

. An equation of state over the entire pressure range was calculated using the observed variation in low-spin fraction with pressure and a low-spin bulk modulus of K T0 = 253(30) GPa, derived from the data above 65 GPa. Pronounced softening in the bulk modulus occurs during the spin transition, reaching a minimum at 50 GPa (∼1500 km) where the bulk modulus of Fe-Al phase D is about 35% lower than Fe-Al-bearing silicate perovskite. Recovery of the bulk modulus at 50-65 GPa results in a structure that has a similar incompressibility as silicate perovskite above 65 GPa. Similarly, the bulk sound velocity of Fe-Al phase D reaches a minimum at ∼50 GPa, being about 10% slower than silicate perovskite. The potential association of Fe-Al phase D with subducted slabs entering the lower mantle, along with its elastic properties through the Fe 3+ spin transition predicted at 1200-1800 km, suggests that phase D may provide an alternative explanation for small-scale mid-lower mantle seismic scatterers and supports the presence of deeply recycled sediments in the lower mantle