The activities of metal-detectorists and other finders and collectors of archaeological objects are increasingly of interest for researchers in archaeology and related disciplines. In this methods article, the authors introduce semi-structured archaeological object interviews—inspired by the object interview in sociology—as a means of observing the meanings and biographies that finder-collectors create for, and with, the objects in their stewardship. The challenges and opportunities for researchers using this method are explored and the authors offer reflections from in-the-field experiences with finder-collectors in Flanders, Finland and Norway.

We define truncated displays over rings in which a prime $p$ is nilpotent, we associate crystals to truncated displays, and we define functors from truncated displays to truncated Barsotti–Tate groups.

We present a process for manufacturing printable thin-film transistors (TFTs) that is based on solution processing and direct inkjet printing of polymer semiconductors, dielectrics, and conductors, as well as inorganic nanoparticle conductors. We show that the high device yield, uniformity, and resolution required for thin-film electronic applications can be achieved by using a substrate that contains a surface energy pattern to control the flow and spreading of inkjet droplets. This technique overcomes many of the limitations of current inkjet printing technology related to its limited droplet placement accuracy. We demonstrate the potential of this printing-based TFT manufacturing process with the fabrication of 50 dpi active-matrix, polymer dispersed liquid-crystal and Gyricon Smartpaper electronic paper displays.

There is still fierce debate in the international community regarding the use and standards of electronic chart data and equipment. Whilst the standards for ecdis are now virtually complete and type-approved equipment will be entering the market during 1998, there is currently no IMO/IHO compliant enc data service from any national hydrographic office. It is expected that it will be 1 to 2 years before there is any appreciable quantity of enc data supported by a proper update service. It will be many more years before enc data becomes available to match the present coverage of paper charts, but we can expect that most major routes and the port entries of the majority of the world's trading nations will be available within a few years. This situation is examined, together with the ideas that IMO is considering to improve the availability of official electronic chart data. In addition, the distribution of electronic charts is discussed and the future trends in navigation that will occur with the availability of ecdis equipment and related data are explored.

A simulator experiment was conducted to determine the potential benefits of path prediction on the navigational performance of channel-bound vessels. Channel pilots had to sail an approach channel under critical conditions in a deep-draught vessel. For the navigation task, basic radar information was used, supplemented by three different path predictors. Predictor (a) was based on an accurate fast-time hydrodynamic model of the vessel and showed the exact future path of the vessel. Both other path predictors were less accurate, relatively simple extrapolators; predictor (b) was based on a speed and rate of turn extrapolator and showed a curved representation of the future path; predictor (c) was based on a linear speed and course extrapolator and showed the ground velocity vector. Navigational performance was determined in terms of deviation from the planned route. The results indicate that the relatively simple extrapolator (b) supported the navigational task as effectively as the highly accurate path predictor (a). In comparison with the linear extrapolator (c), the navigational accuracy increased by a factor of two. It is concluded that support in anticipating the vessel's rate of turn is essential for accurate navigation. Implications of the use of path prediction for ship control are discussed.

E-beam pumped lasers are attractive for Laser Cathode Ray Tubes (LCRT) in projection displays and a variety of applications typically associated with optically pumped lasers. For the first time an InGaN/GaN multiple quantum well (MQW) in-plane laser pumped by surface normal pulse and scanning electron beams was demonstrated. Pumping at room temperature (RT) and 80 K showed peak stimulated emission wavelengths of 402 and 409 nm with a full width half maximum (FWHM) of 0.6 nm and 1.2 nm, respectively. The threshold electron beam current densities have been estimated as 60 A/cm2 for 35 keV electron energy at 80 K using scanning e-beam pumping and 200-300 A/cm2 at RT using pulsed e-beam pumping with a maximum electron energy of 150 keV. At 80 K, light output of 150 mW was measured out of one facet at an e-beam current of 1.7 mA.