The Arcminute Microkelvin Imager is a pair of interferometer arrays operating with six frequency channels spanning 13.9-18.2 GHz, for observations on angular scales of 30 arcsec-10 arcmin and for declinations greater than −15 • ; the Small Array has a sensitivity of 30 mJy s −1/2 and the Large Array has a sensitivity of 3 mJy s −1/2 . The telescope is aimed principally at Sunyaev-Zel'dovich imaging of clusters of galaxies. We discuss the design of the telescope and describe and explain its electronic and mechanical systems.

Low dimensional semiconductor quantum dots (<10 nm) have received great attention for potential use in biomedical applications (diagnosis and therapy) for which larger nanoparticles (>10 nm) are not suitable. Here, we demonstrate a green, biogenic synthesis route for making CdS quantum dots (QDs) with 2-5 nm particle size using tea leaf extract (Camellia sinensis) as a toxic-free particle stabilizing agent. We have explored the biological activity of these CdS QDs in different applications, namely; a) antibacterial activity b) bioimaging and c) apoptosis of lung cancer cells. The antibacterial activity of the CdS QDs has been studied against different types of bacteria growth, showing that CdS QDs effectively inhibit the bacterial growth and exhibit cytotoxicity towards A549 cancer cells when compared to a control (no QD treatment). We have compared this cytotoxicity effect on A549 cancer cells with a standard drug, cisplatin, showing comparable results. Additionally, these CdS QDs produce high contrast fluorescence images of A549 cancer cells indicating a strong interaction with the cancer cell. To further understand the role of CdS QDs in bioimaging and cytotoxicity effect in A549 cells, fluorescence emission and flow cytometry analysis were carried out. The fluorescence emission of CdS QDs were recorded with λexc= 410 nm, showing concentration dependence fluorescence emission centered at 670 nm. From the flow cytometry analysis, it is confirmed that the CdS QDs are arresting the A549 cell growth at the S phase of cell cycle, inhibiting further growth of lung cancer cell. The multifunctional advantages of Camellia sinensis extract mediated green CdS QDs will be of widespread interest in implementing in-vivo based bioimaging and therapeutic cancer treatment applications.

Perovskite solar cells have emerged as a promising and highly efficient solar technology. Despite efficiencies continuing to climb, the prospect of industrial manufacture is hampered by concerns regarding the safety...

The 9C survey of radio sources with the Ryle Telescope at 15.2 GHz was set up to survey the fields observed with the cosmic microwave background telescope, the Very Small Array. In our first paper, we described three regions of the survey, constituting a total area of 520 deg2 to a completeness limit of ≈25 mJy. Here we report on a series of deeper regions, amounting to an area of 115 deg2 complete to ≈10 mJy and of 29 deg2 complete to ≈5.5 mJy. We have investigated the source counts and the distributions of the 1.4 to 15.2 GHz spectral indices (α15.21.4) for these deeper samples. The whole catalogue of 643 sources is available online. Down to our lower limit of 5.5 mJy, we detect no evidence for any change in the differential source count from the earlier fitted count above 25 mJy, n(S) = 51(S/Jy)−2.15 Jy−1 sr−1. We have matched both our new and earlier catalogues with the NRAO VLA Sky Survey (NVSS) catalogue at 1.4 GHz and selected flux‐limited samples at both 15 and 1.4 GHz. As expected, we find that the proportions of sources with flat and rising spectra in the samples selected at 15 GHz are significantly higher than those in the samples selected at 1.4 GHz. In addition, for 15‐GHz samples selected in three flux density ranges, we detect a significant shift in the median value of α15.21.4: the higher the flux densities the higher the proportions of sources with flat and rising spectra. In our area complete to ≈10 mJy, we find five sources between 10 and 15 mJy at 15 GHz, amounting to 4.3 per cent of sources in this range, with no counterpart in the NVSS catalogue. This implies that, had we relied on NVSS for locating our sources, we could have missed a significant proportion of them at low flux densities. Our results illustrate the problems inherent in using a low‐frequency catalogue to characterize the source population at a much higher frequency and emphasize the value of our blind 15.2‐GHz survey.