On phenomenological failure criteria for composite bolted joint analysis

There has been a recent trend to use phenomenological strength models in combination with point stress or average stress failure criteria to form strength models for the analysis of composite bolted joints. Several papers published using these approaches have demonstrated practical reductions in the size of the empirical data base required to perform bolted joint analysis for specific materials and laminates. Since the inception of phenomenological failure models for bolted joints several refinements have been proposed, but the generality of the method is not clearly defined. This paper addresses the concepts underlying the formulation of these strength models, compares the capabilities of several commonly used failure criteria and discusses the limits of applicability through example analyses and comparison with experimental data. The results indicate that differences in predicted strengths for the models examined were insignificant. Failure mode predictions based on single point failure location information varied from model to model and differed significantly from experimentally observed failure modes for some geometries. The models cannot be applied with confidence for the analysis of a wide class of laminates and geometries without calibrating the model through empirical data.     

Controlled prospective longitudinal study of women with cancer: II. Psychological outcomes.

The incidence and etiology of major life difficulties for women with survivable cancer were studied. Women with early stage cancer (n?=?65) were assessed after diagnosis but prior to treatment and reassessed at 4, 8, and 12 mo posttreatment. Two matched comparison groups, women diagnosed and treated for benign disease (n?=?22) and healthy women (n?=?60), were also assessed longitudinally. Results for 4 life areas are reported: (a) Emotional response to the life-threatening diagnosis and anticipation of treatment was characterized by depressed, anxious, and confused moods, whereas the response for women with benign disease was anxious only; these responses were transitory. (b) There was no evidence for a higher incidence of relationship dissolution or poorer marital adjustment; however, 30% of the women treated for disease reported that their partners may have had some sexual difficulty. (c) There was no evidence for impaired social adjustment. (d) Women treated for cancer retained their employment; however, their involvement was significantly reduced during recovery. Data suggest "islands" of significant life disruption following cancer, which do not appear to portend global adjustment vulnerability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Snowpack response in the Assiniboine-Red River basin associated with projected global warming of 1.0 °C to 3.0 °C

This study assesses snow response in the Assiniboine-Red River basin, located in the Lake Winnipeg watershed, due to anthropogenic climate change. We use a process-based distributed snow model driven by an ensemble of eight statistically downscaled global climate models (GCMs) to project future changes under policy-relevant global mean temperature (GMT) increases of 1.0 °C to 3.0 °C above the pre-industrial period. Results indicate that basin scale seasonal warmings generally exceed the GMT increases, with greater warming in winter months. The majority of GCMs project wetter winters and springs, and drier summers, while autumn could become either drier or wetter. An analysis of snow water equivalent (SWE) responses under GMT changes reveal higher correlations of snow cover duration (SCD), snowmelt rate, maximum SWE (SWE_max) and timing of SWE_max with winter and spring temperatures compared to precipitation, implying that these variables are predominantly temperature controlled. Consequently, under the GMT increases from 1.0 °C to 3.0 °C, the basin will experience successively shorter SCD, slower snowmelt, smaller monthly SWE and SWE_max, earlier SWE_max, and a transition from snow-dominated to rain-snow hybrid regime. Further, while the winter precipitation increases for some GCMs compensate the temperature-driven changes in SWE, the increases for most GCMs occur as rainfall, thus limiting the positive contribution to snow storage. Overall, this study provides a detailed diagnosis of the snow regime changes under the policy-relevant GMT changes, and a basis for further investigations on water quantity and quality changes.     

Development of a Weather Forecasting Code: A Case Study

Computational science is increasingly supporting advances in scientific and engineering knowledge. The unique constraints of these types of projects result in a development process that differs from the process more traditional information technology projects use. This article reports the results of the sixth case study conducted under the support of the Darpa High Productivity Computing Systems Program. The case study aimed to investigate the technical challenges of code development in this environment, understand the use of development tools, and document the findings as concrete lessons learned for other developers' benefit. The project studied here is a major component of a weather forecasting system of systems. It includes complex behavior and interaction of several individual physical systems (such as the atmosphere and the ocean). This article describes the development of the code and presents important lessons learned.     

Hepatic elimination of diazepam: interactions with albumin, desflurane and sevoflurane

We have studied the effect of sevoflurane and desflurane on the hepatic elimination of diazepam, by incubating slices of rat livers in a closed system. Protein free and protein containing (albumin 10 g litre-1) buffers were used to examine the effect of the anaesthetics on enzyme activity and diazepam binding to albumin. Both anaesthetics (in concentrations of 0.5, 1.5 and 3.0 mmol litre-1) reduced the elimination of diazepam slightly in the absence of albumin, while the presence of the protein increased elimination to a maximum of 30% at the greatest concentration of the anaesthetics. These data support previous observations that volatile anaesthetics may interact pharmacokinetically with both liver enzyme activity and drug binding to albumin.     

Healing substrates with mobile, particle-filled microcapsules: designing a 'repair and go' system.

We model the rolling motion of a fluid-driven, particle-filled microcapsule along a heterogeneous, adhesive substrate to determine how the release of the encapsulated nanoparticles can be harnessed to repair damage on the underlying surface. We integrate the lattice Boltzmann model for hydrodynamics and the lattice spring model for the micromechanics of elastic solids to capture the interactions between the elastic shell of the microcapsule and the surrounding fluids. A Brownian dynamics model is used to simulate the release of nanoparticles from the capsule and their diffusion into the surrounding solution. We focus on a substrate that contains a damaged region (e.g. a crack or eroded surface coating), which prevents the otherwise mobile capsule from rolling along the surface. We isolate conditions where nanoparticles released from the arrested capsule can repair the damage and thereby enable the capsules to again move along the substrate. Through these studies, we establish guidelines for designing particle-filled microcapsules that perform a 'repair and go' function and thus, can be utilized to repair damage in microchannels and microfluidic devices.     

Large Particle Size Distribution in Five U.S. Cities and the Effect on a New Ambient Participate Matter Standard (PM10)

A mobile aerosol-sampling system was used to determine the large particle ambient aerosol size distribution (up to approximately 100 μm particle diameter) in five cities across the United States: Birmingham, Alabama; Research Triangle Park, North Carolina; Philadelphia, Pennsylvania; Phoenix, Arizona; and Riverside, California. A mobile wide range aerosol classifier (WRAC) developed at the University of Florida was used. The study shows that any measurement of ambient particulate matter with a size-fractionating inlet sampler will be influenced by the ambient particle size distribution.

Mass distribution measurements determined by the WRAC were compared with mass measurements obtained simultaneously using TSP Hi-Vol and 15 μm cut-size inhalable particulate network samplers. Aerosol size-classification results showed the presence of a large particle mass mode at all sites sampled. The position and magnitude of the large particle mode varied and was not a simple function of concentration. The percentage of the total aerosol mass collected by the present EPA reference method high-volume air sampler varied from about 85 to 95%. The percentage of total aerosol mass less than 10 μm varied from about 50 to 90%, depending on the sampling location and sampling condition.     

With regard to "The role of air plethysmography in monitoring results of venous surgery"

By homology to the mgt gene (encoding a macrolide glycosyltransferase) from Streptomyces lividans, a 3.3-kb DNA fragment from the oleandomycin producer, Streptomyces antibioticus, was cloned and sequenced. Analysis of the sequence revealed the presence of the 3' end of a gene (ORF1) and two complete ORFs (ORF2 and oleD), all of them translationally coupled. The deduced product of the sequenced region of ORF1 contained the typical signature of integral membrane proteins responsible for the translocation of substrates across the membrane. The ORF2 product did not show significant similarity with proteins in databases, but contains an N-terminus leader peptide region characteristic of secreted proteins, and a lipid attachment site motif characteristic of membrane lipoproteins synthesized with a precursor signal peptide. The oleD product showed clear similarity with several UDP-glucuronosyl- and UDP-glycosyl-transferases from different origins and particularly with the mgt gene from S. lividans, and might encode a glycosyltransferase activity capable of inactivating macrolides. It is proposed that these three genes could participate in the intracellular glycosylation of oleandomycin and its secretion during antibiotic production.