A potential metallographic technique for the investigation of pipe bombings

This study was conducted in an attempt to develop a metallographic method for the investigation of pipe bombings. Three common pipe materials, ASTM A53 steel, AISI 304L stainless steel, and 6061-T6 aluminum, were shock-loaded using five high explosives and three propellants. The explosives used were ANFO, Composition C4, C6 detasheet, nitroglycerine-based dynamite, and flake TNT. The propellants used were FFFFg black powder. Red Dot smokeless powder, and Turbo Fuel A. The post-blast microstructure, hardness, and, in the case of 304L, transformed martensite content were examined for each test. The damage done to the microstructure was found to increase with increasing detonation velocity of the explosives and increase in pressure generated by the shock-metal interaction. Material hardness and, in the case of 304L, martensite content showed a sharp increase followed by a plateau as the shock pressure and detonation velocity increased.     

Introduction to special issue on ‘professional insecurities’

Introduction

Introduction to special issue on professional insecurities     

Commentaries on Brunner and Willard’s ‘professional insecurities’

Commentary

Commentaries on Brunner and Willards professional insecurities     

Integrating Voting Theory and Roll Call Analysis: A Framework

Scholars of legislative studies typically use ideal point estimatesfrom scaling procedures to test theories of legislative politics.We contend that theory and methods may be better integratedby directly incorporating maintained and to be tested hypothesesin the statistical model used to estimate legislator preferences.In this view of theory and estimation, formal modeling (1) providesauxiliary assumptions that serve as constraints in the estimationprocess, and (2) generates testable predictions. The estimationand hypothesis testing procedure uses roll call data to evaluatethe validity of theoretically derived to be tested hypothesesin a world where maintained hypotheses are presumed true. Wearticulate the approach using the language of statistical inference(both frequentist and Bayesian). The approach is demonstratedin analyses of the well-studied Powell amendment to the federalaid-to-education bill in the 84th House and the Compromise of1790 in the 1st House.     

The fraction of disability caused at work

Disability has high societal and personal costs. Various disparate federal and state programs attempt to address the economic and social needs of people with disabilities. Presumably workplace injuries and accidents are an important source of disability. Yet separate public policies and research literatures have evolved for these two social problems--disability and workplace injuries--despite their relatedness. This article seeks to document the overlap between these two phenomena in estimating the proportion of the disabled population whose disability was caused by workplace injury, accident, or illness using the Health and Retirement Study of 1992. The results point toward the need for initiatives to reduce disability that focus on work-related causes, which are a common pathway to disability, and that may result in substantial savings in federal programs.     

Suicide Attempts and Self-Image Among Turkish Adolescents

The objective of this paper is to report on the role of self-image as an internal factor in suicide attempts of adolescents. Three groups of adolescents, suicide attempters (n = 33), nonsuicidal psychiatric outpatients (n = 50), and normal controls (n = 50), were administered Offer Self-Image Questionnaire, Beck Depression Inventory, Symptom Check List-90-R, and a socio-demographic questionnaire. The factors discriminating suicidal adolescents from the other 2 groups were increased number of siblings, being the older children, and negativity in the familial aspect of the self-image. The self-image factor was specific for suicidal girls but not for boys. Disturbance in the development of the self-image, especially in its relationship with other family members is an important risk factor in attempted suicides by female adolescents. This brings up the importance of including the family in the treatment of suicidal adolescents. None of the factors evaluated in this study are significant in attempted suicides by males. This point needs further research.