Ephemera in the art library

Art libraries acquire a large amount of ephemeral material which creates a unique resource on the history of contemporary art. Librarians have to decide what should be retained, how it should be stored, and how the material can best be accessed. Increasingly there is pressure to digitise in order to promote collections, but how effective this process is in terms of ephemeral material remains a real question. A survey of prominent collections in London and New York has helped to inform future plans for the ephemera held by the library at Chelsea College of Art & Design

In edition: artists’ multiples in an academic library

The artist's multiple is difficult to define, but could be described as an original artwork produced in an edition of two or more. At Chelsea College of Art and Design, the artists' multiples collection was developed to give students first-hand experience of original work by artists, something that is rarely included in the special collections of art libraries. This article examines the history and development of this unique collection of objects, and how it has enabled the library to play an active part in the life and work of the academic community it serves

Laser ignition of iso-octane air aerosols

Iso-octane aerosols in air have been ignited with a focused Nd:YAG laser at pressures and temperatures of 100kPa and 270K and imaged using schlieren photography. The aerosol was generated using the Wilson cloud chamber technique. The droplet diameter, gas phase equivalence ratio and droplet number density were determined. The input laser energy and overall equivalence ratio were varied. For 270mJ pulse energies initial breakdown occurred at a number of sites along the laser beam axis. From measurements of the shock wave velocity it was found that energy was not deposited into the sites evenly. At pulse energies of 32mJ a single ignition site was observed. Overall fuel lean flames were observed to locally extinguish, however both stoichiometric and fuel rich flames were ignited. The minimum ignition energy was found to depend on the likelihood of a droplet existing at the focus of the laser beam

Book Review: The Business of Charity: The Woman’s Exchange Movement, 1832-1900

Review of The Business of Charity: The Woman’s Exchange Movement, 1832-1900 by Kathleen Waters Sande

Positive and negative magnetocapacitance in magnetic nanoparticle systems

The dielectric properties of MnFe$_2$O$_4$ and $\gamma$-Fe$_2$O$_3$ magnetic nanoparticles embedded in insulating matrices were investigated. The samples showed frequency dependent dielectric anomalies coincident with the magnetic blocking temperature and significant magnetocapacitance above this blocking temperature, as large as 0.4% at H = 10kOe. For both samples the magnetic field induced change in dielectric constant was proportional to the square of the sample magnetization. These measurements suggest that the dielectric properties of magnetic nanoparticles are closely related to the disposition of magnetic moments in the system. As neither bulk gamma-Fe2O3 nor MnFe2O3 are magnetoelectric materials, this magnetodielectric coupling is believed to arise from extrinsic effects which are discussed in light of recent work relating magnetoresistive and magnetocapacitive behavior.Comment: 3 pages, 3 figure

Oxygen vacancy enhanced room temperature ferromagnetism in Al-doped MgO nanoparticles

We have investigated the room temperature ferromagnetic order that develops in Al-substituted magnesium oxide, Mg(Al)O, nanoparticles with Al fractions of up to 5 at.%. All samples, including undoped MgO nanoparticles, exhibit room temperature ferromagnetism, with the saturation magnetization reaching a maximum of 0.023 emu/g at 2 at.% of Al. X-ray photoelectron spectroscopy identifies the presence of oxygen vacancies in both doped and undoped MgO nanoparticles, with the vacancy concentration increasing upon vacuum annealing of Mg(Al)O, resulting in two-fold enhancement of the saturation magnetization for 2 at.% Al-doped MgO. Our results suggest that the oxygen vacancies are largely responsible for room temperature ferromagnetism in MgO.Comment: 4 figure