Planned versus actual duration of drug abuse treatment. Reconciling observational and experimental evidence

The purpose of the study was to evaluate the associations of planned versus actual duration of drug abuse treatment with psychosocial outcomes and drug use at follow-up. A randomized trial was conducted in a modified therapeutic community in which 444 clients were assigned to programs with planned durations of either 3 or 6 months. Outcomes were psychosocial measures assessing changes in mood and in stage of behavior change between admission and exit and return to drug use and patterns of use 2 to 6 months after exit. Planned duration was not associated with any of the outcomes. A longer actual length of stay was, however, associated with greater improvements in the mood variables; lower rates of drug use at follow-up; and, among those using drugs at follow-up, a longer time from exit to first drug use. Intention-to-treat analyses supported these results. Randomized controlled trials are needed to distinguish the effects of planned duration and actual length of stay.     

Voluntary and professional disaster-workers: similarities and differences in reactions

Forty-three rescuers responding to a bus crash that killed 12 children and 4 adults and injured many more answered questionnaires at 1 and 13 months following the crash. This study compared the responses of the voluntary and professional helpers, using the Impact of Event Scale (IES) and the General Health Questionnaire (GHQ). For all helpers taken together, the decline in IES-intrusion and IES-total scores was significant from 1 to 13 months. The voluntary helpers reported significantly more intrusion and avoidance on the IES at 1 month than professional helpers, and for avoidance the voluntary helpers still evidenced a significantly higher score than professional helpers at 13 months. The GHQ scores at 13 months reflected that the long-term negative impact of the event was low.     

On the geometrical material structure of anelasticity

Summary G-structures are the geometric backbone of the theory of material uniformity in continuum mechanics. Within this geometric framework, anelasticity is seen as a result of evolving distributions of inhomogeneity reflected as material nonintegrability. Constitutive principles governing thetime evolution of the G-structure underlying the finite-strain theory of anelasticity (e.g., plasticity) are proposed. The material Eshelby stress tensor is shown to be thedriving force behind this evolution. This should allow for a thermodynamically admissible formulation of anelasticity viewed as a G-structure evolution.     

Rotation at the crack tip under uniform heat flow in an infinite medium

A complex analysis of rigid body rotation is presented. The crack-tip rotation for a line crack subjected to steady uniform heat flow is obtained in terms of thermal stress intensity factor in shear mode of the crack, the material and thermal parameters and coordinates of points close to the crack tip. The shear strip configuration is analysed on the basis of rotation and displacement at the end of the shear strip.     

Effect of beam voltage on the properties of aluminium nitride prepared by ion beam assisted deposition

The effects of nitrogen-beam voltage on the structure, stress, energy band gap and hardness of AIN thin films deposited on Si (111), Si (100) and sapphire (0001) by ion beam assisted deposition (IBAD) are reported. As the nitrogen-beam voltage was increased from 50 to 200 V, the stress and disorder in the AIN films increased as determined by X-ray diffraction, FTIR and Raman spectroscopy. The preferred orientation of the film's c-axis changed from completely normal to the film at 100 V, to a mixture of normal and in the plane of the film at 200 V. For AIN films deposited under the same conditions, the films were more highly oriented on sapphire (0001) than in Si (111). The hardness of the films increased from 18.2 to 23.7 GPa with the nitrogen-beam voltage, and possible reasons for this change in hardness are considered.     

Erbium-doped silicon and porous silicon for optoelectronics

Silicon forms the backbone of the microelectronics industry, and possibly, of the optoelectronics industry, hitherto dominated by III/V materials. One of the remaining goals is to build an optical source in silicon. Erbium exhibits luminescent 1.54 μm intra-4f transitions in both silicon and porous silicon. This paper reviews the work which has been carried out in this field and discusses some possible additional applications of erbium-doped silicon in optoelectronics, such as a novel on-chip temperature sensor.     

Sequential discrete multilevel automated system for recording electron-diffraction patterns

This article considers a discrete sequential multilevel automated system for recording electron-diffraction patterns. A comparative analysis is presented, along with experimental results that make it possible to evaluate the effectiveness of the technical decisions on which the device is based. The general design of the system is presented. Translated from Izmeritel'naya Tekhnika No. 5, pp. 16–18, May, 1996.