Correlates of sexual assault in a sample of male African American crack cocaine users

Although numerous studies have reported an association between substance use and sexual assault, little is known about the impact of sexual assault on male African American crack cocaine users. This study found that from a sample of 137 respondents from Houston, Texas, one-third reported having been sexually assaulted at least once during their lifetime. Respondents who reported sexual assault were using cocaine more often and were more likely to be physically dependent on drugs and to report greater numbers of physical health problems due to their drug use. However, no differences were identified in respect of reported mental health problems, or problems with family, friends or the workplace associated with drug use. The findings suggest further research as to the impact of sexual assault on male crack cocaine users is warranted and that clinical staff working with male substance users require some awareness of the impacts of sexual assault.

The impact of religious affiliation while growing up on substance use by African-American crack cocaine users

This paper explores the relationship between church attendance while growing up and the substance use issues reported by 159 African American crack cocaine users in Houston Texas. It was found that more frequent juvenile attendance at church was associated with being less likely to suffer withdrawal symptoms or to take drugs to avoid withdrawal. However/ there were no differences between regular/ irregular and non-attendees in respect of number of substance use issues reported or attendance at a self help group for substance use/ even though these are often faith-based. The relevance of including questions on religious participation when young in screening instruments to be used with adult substance abusers is questioned.

Medication compliance and satisfaction with treatment for HIV disease in a sample of African-American crack cocaine smokers

The development of treatment regimes for African-American HIV-infected crack cocaine users has often been based on assumptions about compliance with medication regimes rather than evidence. This study sought to obtain baseline information on the adherence to antiretroviral medications by members of this important risk population in Houston, Texas. It was found that for only 5 of a range of 16 antiviral medications was there a significant correlation between levels of compliance reported by respondents and their beliefs as to how effective these medications are. Medication compliance was also found not to be associated with frequency of crack cocaine use in the month prior to interview. Furthermore, irrespective of both gender and their reported extent of medication compliance, the respondents tended to report positive relationships with their treating physician, with higher levels of satisfaction reported by women. These results suggest that the majority of African-American crack cocaine users are able to comply with HIV treatment regimes, with more than half (53%) claiming full compliance for one or more medications, and a further one third (31%) claiming compliance more than half the time. Moreover, these findings suggest that they will continue to take antiretroviral medications even if they have doubts about the effectiveness of these medications.

The determination of the local conditions for void initiation in front of a crack tip for materials with second-phase particles

A procedure is proposed to determine, for second-phase particles near a crack tip, the maximum particle stresses at the moment of void initiation by either particle fracture or particle/matrix interface separation. A digital image analysis system is applied to perform a quantitative analysis of corresponding fracture surface regions from stereo image pairs taken in the scanning electron microscope. The fracture surface analysis is used to measure, for individual particles, the crack tip opening displacement at the moment of void initiation and the particle location with respect to the crack tip. From these data, the stress tensor at the moment of void initiation is calculated from the Hutchinson–Rice–Rosengren (HRR) field theory. The corresponding average local stresses within the particle are evaluated by a non-linear Mori–Tanaka-type approach. These stresses are compared to estimates according to the models by Argon et al. [A.S. Argon, J. Im, R. Safoglu, Metall. Trans. 6 (1975) 825] and Beremin [F.M. Beremin, Metall. Trans. 12 (1981) 723]. The procedure is demonstrated on an Al6061–10% Al2O3 metal matrix composite.

Numerical modeling of interactions between a macro-crack and a cluster of micro-defects

The interactions between a macro-crack and a cluster of micro-defects are studied numerically by using a series of special finite elements each containing a defect. These special finite elements, which contain defects such as holes, cracks, and inhomogeneities, are developed based on the hybrid displacement, complex potential and conformal mapping techniques. These hybrid-type elements can be used together with the conventional finite elements without any difficulty. Thus, simple finite element models can be devised to study the interactions between a macro-crack and a cluster of micro-defects. In this paper, the mathematical and finite element modeling procedures for the study of the above-mentioned problems are presented.

Kant, or the crack in the universal : Slavoj Zizek's politicising the transcendental turn

This paper examines Slavoj Zizek’s reading of Immanuel Kant. Its undergirding argument is that Zizek’s work as a whole- up to and including his politically radical statements, which have become more and more prominent since 1997- is conceivable as a project in the rereading of the Kantian ‘Copernican Revolution’ via Lacanian psychoanalysis. Critics now agree that Zizek’s orienting aim is to write a philosophy of politics, as more recent texts, like The Ticklish Subject make clear. (Kay, 2003; Sharpe, 2004; Dean 2006) If Zizek’s philosophy is ultimately a philosophy of politics, however, Zizek’s political philosophy is grounded in a wider post or ‘neo’-Kantian philosophy of subjectivity.
The essay has three major parts. Part I gives Zizek’s reading of Kant on the subject of apperception. Part II recounts Zizek’s pivotal reading of Kant on the sublime, which he ties closely to the problematics of the ‘Transcendental Dialectic’ of the first Critique. Part III then examines Zizek’s conception of subjectivity in terms of the faculties (and especially the faculty of imagination) that Kant argues are involved in the transcendental constitution of objects in the first half of The Critique of Pure Reason.
In the Conclusion, the force of the paper’s subtitle—‘Politicising the Transcendental Turn’—will become manifest. I lay out three principles of Zizek’s ‘neoKantian/Hegelian’ ontology. These also make clear how his philosophy of political agency is grounded in this apparently suprapolitical or solely philosophical reading of Kant.

Quantitative assessment of through-thickness crack size based on Lamb wave scattering in aluminium plates

The interaction of Lamb wave modes at varying frequencies with a through-thickness crack of different lengths in aluminium plates was analysed in terms of finite element method and experimental study. For oblique-wave incidence, both numerical and experimental results showed that the wave scattering from a crack leads to complicated transmission, reflection and diffraction accompanied by possible wave-mode conversion. A dual-PZT actuation scheme was therefore applied to generate the fundamental symmetrical mode (S0) with enhanced energy to facilitate the identification of crack-scattered wave components. The relationship between crack length and the reflection/transmission coefficient obtained with the aid of the Hilbert transform was established, through which the crack length was quantitatively evaluated. The effects of wavelength of Lamb waves and wave diffraction on the properties of the reflection and transmission coefficients were analysed.

Modelling of laser beam spot-weld using 2-D hybrid crack finite elements

Laser beam spot-welding is widely applied to join sheet metals for automotive components especially for thinsheet components in automotive industries. The spot welds in such metallic structures contribute a lot to the integrated strength and fatigue life for the whole structures and they are responsible for their damage or collapse in some loading cases. In this paper, the 2-D hybrid special finite elements each containing an edge crack are employed to study the fracture behaviors of laser beam spot-welds. Hence the calculation accuracy in the vicinity of crack tips is ensured, and a better description of stress singularity with only one hybrid element surrounding one crack is provided. The numerical modeling for laser beam spot-welds subjected to three typical modes ofloadings including tension-lap, shear-lap and angle-clip can be greatly simplified with the applications of such elements. Three specimens under lap-shear, lap-tension and angle clip are devised and analyzed respectively, and main fracture parameters such as stress intensity factors and the initial direction of crack growth are obtained through tinite element analyses. The computed results ti'om numerical examples demonstrate the validity and versatility of the proposed modeling.

Hybrid special finite element method for bi-material crack

In the paper, two novel 2-D hybrid special finite elements each containing an interfacial edge crack, which lies along or vertical to the interface between two materials, are developed. These proposed elements can assure the high precision especially in the vicinity of crack tip and provide a better description of its singularity with only one hybrid element surrounding one interfacial crack, thus, the numerical modeling of fracture analysis on bi-material crack can be greatly simplified. Numerical examples are provided to demonstrate the validity and versatility of the proposed method.

Interfacial energy states of moisture-exposed cracks in mica

Results of crack growth observations on mica in water-containing environments are described. The study focuses on equilibrium crack states for reversed loading cycles, i.e., for initial propagation through virgin solid and subsequent retraction-repropagation through healed or misoriented-healed interfaces. Departures from these equilibrium states are manifest as steady-state forward or backward crack velocities at specific applied loads. The equilibria are thereby interpreted as quiescent, threshold configurations G = W_E, with G the Griffith mechanical-energy-release rate and W_E the Dupré work of adhesion, on crack velocity (v-G) diagrams. Generally, W_E is found to decrease with concentration of water, in accordance with a Gibbs formalism. Hysteresis is observed in the forward-backward-forward crack propagation cycle, signifying a reduction in the adhesion energy on exposure of the open interface to environmental species prior to healing. This hysteresis is especially marked for those interfaces that are misoriented before healing, indicating that the structure of the underlying solid substrate as well as of the intervening fluid is an important consideration in the interface energetics. The equilibrium states for different environments can be represented on a simple energy-level diagram, as differences between thermodynamic end-point states: initial, closed-interface states refer to crystallographic bonding configurations ahead of the crack-tip adhesion zone; final, open interface states refer to configurations behind the crack-tip zone. The significance of this diagram in relation to the fundamental atomic structure of interfaces in fracture and other adhesion geometries, including implications concerning kinetics, is discussed.