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Background: A nationwide survey of family members of people with intellectual and developmental disabilities ranging in age from birth through adulthood was conducted to replicate a similar effort by Wehmeyer and update the knowledge base concerning technology use by people with intellectual and developmental disabilities. Method: Survey responses provided information about use of technology for mobility, hearing and vision, communication, independent living, and in the area of computer use. In addition, survey items queried the use of electronic and information technology devices such as use of email, mobile telephones and digital cameras. Results: Survey results showed that although the use of computers for individuals with intellectual and developmental disabilities is more prevalent, other technology use frequency is much the same as in the late 1990s. However, technology needs did vary among school-age individuals over time. Conclusion: Implications of results for technology use of people with disabilities are discussed through the lens of frequency of use and needs for individuals with disabilities.

Presents a study which featured as-deposited superconducting thin films of Y[sub1]Ba[sub2] Cu[sub3]O[sub7-δ]. Methods used in growing thin films of high-temperature superconducting materials; Description of electrode geometries used separately for the deposition procedure; Details on resistivity and temperature of the films.

Presents a study which utilized nanosecond laser pulse to excite clamped aluminum disks to flexural resonance. Clamped disk theory; Experimental procedure; Results and discussion.

The magnetic properties of single crystal gadolinium-rich [Gd.sub.100-x][Y.sub.x] alloys are investigated using ac susceptibility, magnetization, and ultrasonic techniques, to determine the magnetic phase behavior in the region x [is less than] 10. For [Gd.sub.92.5][Y.sub.7.5], observations are consistent with a canting of the magnetic moment away from the c-axis toward the basal plane at 243 K, and a return toward the c-axis at lower temperatures. The precedence of a phase change at 116 K is confirmed. Index Terms--Ferromagnetic materials, gadolinium alloys, magnetic susceptibility, rare earth alloys.

The elastic constants and electrical transport properties of single-crystal Gd and Gd-Y are measured for Y⩽26 at. %. There are clear features in the elastic constant C[SUB33](T) and in the temperature) derivative of the a-axis resistivity, dρ[SUBa]/dT), at the accepted ferromagnetic Curie temperature (T[SUBC], and at the accepted spin-reorientation at T[SUBSR]. In the Gd-rich Gd-Y, there is a third feature at T[SUP*] below T[SUBSR], which is consistent with evidence for a further second-order transition. A modified magnetic phase diagram for Gd-Y is proposed. [ABSTRACT FROM AUTHOR]

Studies magnetic phases of gadolinium-scandium alloys in the multicritical regime. Method of the study; Results and discussion; Conclusion.

Discusses the temperature dependence of longitudinal ultrasonic velocity in iron and Dural. Waveforms for aluminum alloys; Analysis of the behavior of iron; Temperature dependence of longitudinal velocity.

Transducers have been designed and tested based on a piezoelectric element that is 25 mm thick and conical in cross section. These devices do not require any backing, have low levels of radial mode vibration, and present a small area of contact to the surface of a solid. Theory and experiment are compared, and reasonable results are obtained. [ABSTRACT FROM AUTHOR]

A method is described by which transient ultrasonic Lamb waves may be generated and detected within thin materials, using laser techniques. The material is thin enough that only the two lowest-order modes of Lamb waves need be considered. These are the a0 mode, which is dispersive in the thin plate limit, and the s0 mode, which is not. Signal processing techniques were used to determine the dispersion characteristics of the a0 mode, and the velocity of the s0 mode, in both aluminum and metallic glass samples. From these measurements, it was possible to estimate both the thickness of the samples and their elastic constants. The errors involved in such a measurement are discussed. [ABSTRACT FROM AUTHOR]

The processes that can generate acoustic waves in a sample subjected to a changing magnetic field are discussed. An applied magnetic field with a fast rise time is found to be most efficient for generating magnetomechanical acoustic emission (MAE). The amplitude of the events correlates with the magnetostriction of the material. The shape of a sample affects both the level of magnetization, which can be achieved in a given applied field, and the acoustic modes, which the sample can support. It is demonstrated that MAE excites the fundamental longitudinal resonance of rodlike samples and the way the sample is held affects both the magnitude and frequency of these resonances. When the sample is subjected to tensile stress, the amplitude of the MAE decreases rapidly. However, it is shown that this decrease can be accounted for by an increase in the degree of clamping of the sample ends and that the normalized MAE actually increases initially with tension. [ABSTRACT FROM AUTHOR]

Directivity patterns of laser-generated longitudinal and shear waves in aluminum have been determined experimentally, for laser power densities both above and below the threshold for plasma formation on the target's surface. Comparison of experimental results with theory has allowed generation mechanisms to be identified. Thermoelastic mechanisms predominate in the absence of a plasma, where stresses parallel to the surface are a dominant source characteristic. At higher power densities, momentum transfer from ablating material becomes more important, leading to a source with normal drive components. [ABSTRACT FROM AUTHOR]

Longitudinal, shear, and surface acoustic pulses have been generated by irradiation of free metal surfaces with a Q-switched Nd:YAG laser. Laser energies as low as 3 mJ are sufficient to generate ultrasonic pulses, in various metals, that are readily detected by conventional piezoelectric transducers, without the need for laser focusing. The generation efficiency of longitudinal, shear, and Rayleigh modes has been studied in both the presence and absence of a plasma. Experimental data in graphical form highlight several features of the acoustic source, from which a qualitative model is proposed. [ABSTRACT FROM AUTHOR]