Miniature Design Research Articles

High Definition Radiography

Advances in manufacturing methods and the increased use of processes like electron beam welding and investment casting, have brought unprecedented demands for advanced NDT techniques. Similarly, trends towards compact, miniature design present further problems of access to critical areas. Andrex NDT Products (U.K.) Ltd. new HDR6 unit is specifically designed to meet these demands with a micro‐focus, rod anode configuration that can accept a range of probe sizes each with a complete choice of beam output modes.

Miniature specimen tensile data for high energy neutron source experiments

A miniature tensile specimen technology has been developed in support of high energy neutron irradiated material testing. The work includes miniature specimen design and fabrication technique development, as well as both baseline and irradiated tensile testing. Baseline data obtained using miniature tensile specimens are in good agreement with published values obtained using larger specimen geometries. Tensile data from miniature specimens irradiated up to a high energy, E ∼14 MeV, dose level of 1.10 18 n/cm 2 or 0.003 dpa, have been obtained for annealed and cold worked AISI 316 stainless steel.

Electrets in Miniature Microphones

The electret capacitive microphone element is ideally suited for miniature applications. The simplicity of its structure leads to a straightforward design even in very small devices. Since the electret foil is the only moving element, and the foil-back electrode spacing the only critical dimension, the electret cartridge is simple in design and extremely rugged. Careful design of the cartridge and associated preamplifier is required to minimize the microphone's self noise. The principal aspects of a miniature electret microphone design are discussed, including the cartridge and the preamplifier, and two examples of small omnidirectional microphones are given.

The effects of intertrial interval duration on short-term retention of a two-choice visual-discrimination task by retarded children

The effects of intertrial interval (ITI) duration (the massing and spacing of trials) were assessed in a two-choice visual discrimination task with retarded children of MA 6–8 years. A distinction between two kinds of ITI, inter- and intra-problem, made in terms of like and unlike adjacent responses, allowed for a test of several conflicting theories of memory within a miniature experiment design. The finding of significant retention deficits associated with a longer (20-second) intra-problem ITI indicated that short-term memory was an important factor in performance on this task. The retention loss was related to proactive interference variables. Decay theory received some, but less impressive, support in the interproblem-effects data. The retardate retention function resembled that of normal adults on verbal-learning tasks.

Problems of electron beam machining in miniature circuit design

Problems of electron beam machining in miniature circuit design