A Matter of Substance, July 2010.

A publication of the IDPH Division of Behavioral Health to find out what's happening with Substance Abuse Prevention and Treatment

Linearisable third order ordinary differential equations and generalised Sundman transformations

We calculate in detail the conditions which allow the most general third order ordinary differential equation to be linearised in X'''(T)=0 under the transformation X(T)=F(x,t), dT=G(x,t)dt. Further generalisations are considered.Comment: 33 page

Paramagnetic resonance effect in viscoelastic materials Annual progress report, 1 Jan. - 31 Dec. 1968

Electron paramagnetic resonance investigation of fracture in viscoelastic material

Aeronautical engineering: A special bibliography with indexes, supplement 82, April 1977

This bibliography lists 311 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1977

Experimental approaches for assessing time and temperature dependent performances of fractured laminated safety glass

Laminated glass is for a few decades a well-known product in the construction industry for conferring safety performances to glazing units. Besides to the safeguarding of persons, laminated glass products are contributing to a variety of other safety performances, in case of accidental or attack situations leading to breakage of or crack propagation in the glass panes of a laminated glass unit. The ultimate residual load-bearing capacity of a damaged element can be resumed to one critical load-transfer mechanism, in the form of interlayer ligaments bridging the glass fragments. The characterization for design purposes of the mechanical properties of the interlayer involved in this load-transfer mechanism through the ligament appears however far from obvious. This results from specificities on the one hand of adhesive polymer components and on the other of design and control processes in the building industry. These specificities are mainly related to two aspects : firstly to the time- and temperature dependent behaviour of interlayer materials and their possible sensitivity to ageing effects, and secondly to initially vaguely defined intended fields of use, especially when non-conventional structural applications are within the considered application scope. The combination of these two aspects raises constraints for the development of experimental methods, test configurations and assessment strategies for laminated glass products. This research proposes analysis grids to get an overview of the constitutive elements of application scopes and of the possibilities and limitations for experimental assessment, with purpose to distinguish and estimate different types of border effects. These are used to evaluate the representativeness and the robustness of different test methods and test configurations, corresponding to different experimental scales. An incremental experimental approach has been developed for investigating the time- and temperature dependent performances of damaged laminated glass elements, on the basis of tests on pre-cracked specimens of small dimensions. The assessment of the residual load-bearing capacity of damaged elements used in structural applications was the main focus of these investigations. This research highlights the need for adapting experimental assessment approaches to characterize properties of laminated glass products for design purposes with respect to their post-fracture performances, in comparison with other construction materials. It also explains specific difficulties for obtaining quantitatively meaningful results and the challenges for harmonizing experimental assessment strategies for different applications and products made with a same type of interlayer material

Composite structural materials

A decade long program to develop critical advanced composite technology in the areas of physical properties, structural concept and analysis, manufacturing, reliability, and life predictions is reviewed. Specific goals are discussed. The status of the chemical vapor deposition effects on carbon fiber properties; inelastic deformation of metal matrix laminates; fatigue damage in fibrous MMC laminates; delamination fracture toughness in thermoplastic matrix composites; and numerical analysis of composite micromechanical behavior are presented

Efficiency of purchasing and selling agents in markets with quality uncertainty: The case of illicit drug transactions

illicit drug markets, quality uncertainty, efficient transactions