Food neophobia and mealtime food consumption in 4-5 year old children.

Background: Previous research has documented a negative association between maternal report of child food neophobia and reported frequency of consumption of fruit, vegetables, and meat. This study aimed to establish whether neophobia is associated with lower intake of these food types in naturalistic mealtime situations. Methods: One hundred and nine parents of 4–5 year olds completed questionnaires which included a six-item version of the Child Food Neophobia Scale (CFNS). The children took part in a series of 3 test lunch meals at weekly intervals at school at which they were presented with: chicken, cheese, bread, cheese crackers, chocolate biscuits, grapes and tomatoes or carrot sticks. Food items served to each child were weighed before and after the meal to assess total intake of items in four categories: Fruit and vegetables, Protein foods, Starchy foods and Snack foods. Pearson Product Moment Correlations and independent t tests were performed to examine associations between scores on the CFNS and consumption during lunches. Results: Neophobia was associated with lower consumption of fruit and vegetables, protein foods and total calories, but there was no association with intake of starch or snack foods. Conclusion: These results support previous research that has suggested that neophobia impacts differentially on consumption of different food types. Specifically it appears that children who score highly on the CFNS eat less fruit, vegetables and protein foods than their less neophobic peers. Attempts to increase intake of fruit, vegetables and protein might usefully incorporate strategies known to reduce the neophobic response

Focused Connected Array Antenna as a Broadband Beam-Steering Feed for Quasi-Optical System

This communication proposes a broadband and efficient integrated focal plane array solution based on a near-field focused connected array of slots. The focused aperture provides: 1) broadband and highly efficient illumination of the quasi-optical system and 2) scanning capabilities within a focusing system. The connected array antenna in turn allows for a fully integrated solution that can synthesize a focused aperture while providing broadband impedance matching. Focused connected array antennas enable the coupling to a reflector system over bandwidths in excess of one octave and with aperture efficiencies in excess of 60%. To demonstrate the concept, we present two printed circuit board (PCB) prototypes operating in the band 3-6 GHz and yielding more than 60% reflector aperture efficiency under broadside illumination and allowing to scan one beamwidth at the lowest frequency with a frequency-averaged scan loss of 0.2 dB. The feasibility of scaling this concept to THz frequencies and with dynamic beam-steering capabilities is discussed in the context of a superconducting device.Tera-Hertz Sensin

Improved superconducting hot-electron bolometer devices for the THz range

Improved and reproducible heterodyne mixing (noise temperatures of 950 K at 2.5 THz) has been realized with NbN based hot-electron superconducting devices with low contact resistances. A distributed temperature numerical model of the NbN bridge, based on a local electron and a phonon temperature, has been used to understand the physical conditions during the mixing process. We find that the mixing is predominantly due to the exponential rise of the local resistivity as a function of electron temperature.Kavli Institute of NanoscienceApplied Science

Ultrasensitive Kilo-Pixel Imaging Array of Photon Noise-Limited Kinetic Inductance Detectors Over an Octave of Bandwidth for THz Astronomy

We present the development of a background-limited kilo-pixel imaging array of ultrawide bandwidth kinetic inductance detectors (KIDs) suitable for space-based THz astronomy applications. The array consists of 989 KIDs, in which the radiation is coupled to each KID via a leaky lens antenna, covering the frequency range between 1.4 and 2.8 THz. The single pixel performance is fully characterised using a representative small array in terms of sensitivity, optical efficiency, beam pattern and frequency response, matching very well its expected performance. The kilo-pixel array is characterised electrically, finding a yield larger than 90% and an averaged noise-equivalent power lower than 3 × 10- 19 W/Hz1 / 2. The interaction between the kilo-pixel array and cosmic rays is studied, with an expected dead time lower than 0.6% when operated in an L2 or a similar far-Earth orbit.Tera-Hertz Sensin

Wideband Sub-mm Wave Superconducting Integrated Filter-bank Spectrometer

The design of an octave bandwidth sub-mm wave superconducting on-chip filter-bank spectrometer for Astronomy is presented. An array of THz band-pass filters subdivides the bandwidth 220-440 GHz into channels with a spectral resolution of 400 and an average maximum coupling strength f/ Delta {f} of 40%. The filter-bank performance is assessed by means of a transmission line formalism that approximates its behavior. The chip is under fabrication and its measurements will follow.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz Sensin

Evidence of a Nonequilibrium Distribution of Quasiparticles in the Microwave Response of a Superconducting Aluminum Resonator

In a superconductor, absorption of photons with an energy below the superconducting gap leads to redistribution of quasiparticles over energy and thus induces a strong nonequilibrium quasiparticle energy distribution. We have measured the electrodynamic response, quality factor, and resonant frequency of a superconducting aluminium microwave resonator as a function of microwave power and temperature. Below 200 mK, both the quality factor and resonant frequency decrease with increasing microwave power, consistent with the creation of excess quasiparticles due to microwave absorption. Counterintuitively, above 200 mK, the quality factor and resonant frequency increase with increasing power. We demonstrate that the effect can only be understood by a nonthermal quasiparticle distribution.QN/Quantum NanoscienceApplied Science

Reduced noise in NbN hot-electron bolometer mixers by annealing

Applied Science

Phonon-Trapping-Enhanced Energy Resolution in Superconducting Single-Photon Detectors

A noiseless, photon-counting detector, which resolves the energy of each photon, could radically change astronomy, biophysics, and quantum optics. Superconducting detectors promise an intrinsic resolving power at visible wavelengths of R=E/δE≈100 due to their low excitation energy. We study superconducting energy-resolving microwave kinetic inductance detectors (MKIDs), which hold particular promise for larger cameras. A visible and near-infrared photon absorbed in the superconductor creates a few thousand quasiparticles through several stages of electron-phonon interaction. Here we demonstrate experimentally that the resolving power of MKIDs at visible to near-infrared wavelengths is limited by the loss of hot phonons during this process. We measure the resolving power of our aluminum-based detector as a function of photon energy using four lasers with wavelengths between 1545-402nm. For detectors on thick SiN/Si and sapphire substrates the resolving power is limited to 10-21 for the respective wavelengths, consistent with the loss of hot phonons. When we suspend the sensitive part of the detector on a 110-nm-thick SiN membrane, the measured resolving power improves to 19-52, respectively. The improvement is equivalent to a factor 8±2 stronger phonon trapping on the membrane, which is consistent with a geometrical phonon propagation model for these hot phonons. We discuss a route towards the Fano limit by phonon engineering.Tera-Hertz SensingQN/van der Zant La