A Radio Determination of the Time of the New Moon

The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5--100\,GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of $\sim 10$ GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0$^\circ{}\!\!$.6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was $72.7 \pm 2.2$ in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detectable at $\sim 2^{\circ}$ from the Sun. Our observations at 16\,hr\,36\,min UT indicated that the Moon would have been at closest approach to the Sun 16\,hr\,25\,min earlier; this was the annular solar eclipse of 00\,hr\,00\,min\,UT on 21 May 2012.Comment: 11 pages, 15 figures, accepted for publication in MNRA

Surface Functionalization of Carbon Nanotubes for Energy Applications

Carbon nanotubes (CNTs) are receiving a great deal of attention as a catalyst support for different energy applications, due to their high surface area and high conductivity. Recent literature studies have shown that the application of CNTs mainly depends on their surface functionalization process. Typically, pristine CNTs (as produced) have no functional groups, which is usually considered as an obstacle to their widespread application. In this chapter, we highlight the different techniques used to functionalize the surface of CNTs, including physical and chemical functionalization processes. We show the advantages and the drawbacks of the different functionalization processes. Additionally, we explain in detail the different techniques used to characterize the CNTs before and after functionalization processes. Furthermore, we focus on polymer wrapping techniques of CNTs to create active nanocomposite materials for energy applications, in particular the applications in the agriculture field to fight pollution and make farming activity easier and more efficient

High-resolution magnetic resonance imaging and diffusion tensor imaging of the porcine temporomandibular joint disc

This is the published version. Copyright © 2014 The British Institute of RadiologyObjectives: Diffusion tensor imaging (DTI) is an MRI modality for characterizing the property, microstructural organization and function in tissues such as the brain and spinal cord. Prior to this investigation, DTI had not been adapted for studies of the temporomandibular joint (TMJ) disc. Objectives were to test the feasibility of DTI to evaluate the porcine TMJ disc and to use DTI to observe differences in magnitude of anisotropy of water diffusion between TMJ disc regions. Methods: Five adult pig TMJs were scanned on a 9.4 Tesla horizontal bore MRI scanner using an inductively coupled surface coil. High-resolution gradient-echo and diffusion-weighted spin-echo based images were obtained. The mean diffusivity and fractional anisotropy (FA) were computed in different regions of the disc. Two observers were calibrated to review the two-dimensional and three-dimensional images. Polarized light microscopy was used as the gold standard for collagen fibre orientation. Results: In the sagittal plane, the mean diffusivity was higher in the posterior (1.28±0.10×10−3 mm−2 s−1) and anterior (1.27±0.08×10−3 mm−2 s−1) bands compared with the intermediate zone (0.96±0.01×10−3 mm−2 s−1), and the FA index was also lowest in the intermediate zone. In the coronal plane, the mean diffusivity was higher in the medial (1.42±0.01×10−3 mm−2 s−1) and lateral (1.21±0.12×10−3 mm−2 s−1) aspects than in the centre (1.09±0.08×10−3 mm−2 s−1), and the FA index was also lowest in the centre. Conclusions: DTI is a useful method for non-invasively characterizing the structure/property relationships of the porcine TMJ disc

From Gapped Excitons to Gapless Triplons in One Dimension

Often, exotic phases appear in the phase diagrams between conventional phases. Their elementary excitations are of particular interest. Here, we consider the example of the ionic Hubbard model in one dimension. This model is a band insulator (BI) for weak interaction and a Mott insulator (MI) for strong interaction. Inbetween, a spontaneously dimerized insulator (SDI) occurs which is governed by energetically low-lying charge and spin degrees of freedom. Applying a systematically controlled version of the continuous unitary transformations (CUTs) we are able to determine the dispersions of the elementary charge and spin excitations and of their most relevant bound states on equal footing. The key idea is to start from an externally dimerized system using the relative weak interdimer coupling as small expansion parameter which finally is set to unity to recover the original model.Comment: 18 pages, 10 figure

Low Incidence of Androgen Receptor Mutation Among Egyptian Children with Androgen Resistance

Introduction: In Egypt, disorders of sex development (DSD) constitute a significant entity among the birth defect list. Previous studies have reported that end organ androgen unresponsiveness, i.e. Androgen resistance, was the most prevalent underlying mechanism among Egyptian 46,XY DSD cases. Based on cytogenetic and hormonal diagnostic criteria as well as few sporadic case reports, it was proposed that androgen receptor (AR) defects [i.e. Androgen insensitivity syndrome (AIS), OMIM#300068] might constitute a major etiology within this category. However, this has never been systematically ascertained through an AR molecular diagnostic approach. Aim of the Work: The current study aimed to assess the role of AR mutations as an underlying etiology among a sample of Egyptian 46,XY DSD pediatric patients presenting with androgen end organ unresponsiveness. Patients and Method: In the current study, 21 children [ag