Mechanical behaviour of iron oxide scale: Experimental and numerical study

The paper addresses the identification of constitutive parameters of thick, brittle layers on metal substrates. Application is to the iron oxide behaviour during hot rolling processes of steel, where oxide scale breaking and embedding is one of the major causes of surface defects. Contact management of a FEM software has been adapted in order to address the transitions corresponding to transverse oxide fracture, along with two other mechanisms, namely delamination and interfacial stick/slip. It is applied to the hot strip rolling process to show pre-bite cracking and its consequences (“micro-extrusion” of the metal). To approximate the stress state prevailing at roll bite entry, the Four-Point Hot Bending Test (4PHBT) has been selected for the measurement of oxide properties. Oxidation is made in situ in the test rig under conditions similar to a hot strip mill (HSM) environment. Comparison of load-deflection curves for oxidized and non-oxidized samples allows the mechanical properties of the oxide to be determined. Above a critical temperature T_c - around 700 °C, but depending on strain rate - the oxide is ductile (with a very narrow plastic strain range, ?_p < 10⁻²) and elastic-viscoplastic (EVP) constitutive parameters are identified numerically. Below T_c, brittleness is manifested by an array of transverse, through-thickness cracks. Acoustic emission (AE) has been used to help detect the onset of fracture, while numerical simulation gives the critical fracture stress at the corresponding point of the load-deflection curve. Results for four low carbon steel grades are compared.     

Spatialized Audio Environmental Awareness for Blind Users with a Smartphone

Numerous projects have investigated assistive navigation technologies for the blind community, tackling challenges ranging from interface design to sensory substitution. However, none of these have successfully integrated what we consider to be the three factors necessary for a widely deployable system that delivers a rich experience of one’s environment: implementation on a commodity device, use of a pre-existing worldwide point of interest (POI) database, and a means of rendering the environment that is superior to a naive playback of spoken text. Our “In Situ Audio Services” (ISAS) application responds to these needs, allowing users to explore an urban area without necessarily having a particular destination in mind. We describe the technical aspects of its implementation, user requirements, interface design, safety concerns, POI data source issues, and further requirements to make the system practical on a wider basis. Initial qualitative feedback from blind users is also discussed.     

Mentalization in adult attachment narratives: Reflective functioning, mental states, and affect elaboration compared.

Relationships between three measures of mentalization (reflective function, mental states, and verbal elaboration of affect), attachment status, and the severity of axis I and axis II pathology were examined. Seventy-three adults, both ex-psychiatric patients and nonclinical volunteers were administered the Adult Attachment Interview (AAI). Comparisons between the three measures indicate that they share some aspect of a core mentalization process and that each illuminates a specific component. Reflective function was the only predictor of attachment status. The number of axis I diagnoses is partly explained by attachment insecurity, but the capacity to generate high-level defensive mental states as well as increments in verbal affect elaboration further contribute to the model. Finally, increments in affect elaboration, as well as augmentations in high-level defensive activity and reflective function are all associated with decreases in the number of axis II diagnoses, over and above the contribution of attachment status and axis I pathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

DARPA Information Assurance Program dynamic defense experimentsummary

Several types of experiments are being conducted by the Defense Advanced Research Projects Agency (DARPA) Information Assurance (IA) Program in DARPA's IA Lab. This research program is driven by concepts of strategic cyberdefense. Each experiment involves a carefully formulated hypothesis that is intended to be either supported or refuted by the experimental testing. In many cases, “red team” attackers participate in all phases of the experiment and contribute to generating the data required to test the hypothesis. The red team is usually structured to model a well-resourced adversary, such as a foreign, national intelligence agency. The particular experiment described here explored one aspect of the IA program's grand hypothesis of dynamic defense: “Dynamic modification of defensive structure improves system assurance.” This experiment concentrated on the assertion that autonomic response mechanisms can improve overall system assurance by thwarting an attack while it is underway. In most cases, each attack in this experiment was run first with only “prevent and detect” mechanisms enabled, then repeated with “prevent, detect, and respond mechanisms” enabled. The key result of this experiment is that the hypothesis was supported     

Review of Les troubles anxieux: Approche cognitive et comportementale.

Reviews the book, Les troubles anxieux: Approche cognitive et comportementale by Robert Ladouceur, André Marchand, and Jean-Marie Boisvert (1999). This volume offers an excellent source of information for private practitioners, students, and trainees. After a brief introduction, each chapter describes a particular anxiety disorder and explores the following topics: DSM-IV diagnosis, prevalence and comorbidity, major elements of differential diagnosis, evaluation and instrumental measures, intervention strategies, and future research. Case studies are included. The authors clearly transmit current scientific knowledge on anxiety disorders and therapeutic applications. The cognitive behavioral approach integrates therapeutic strategies with demonstrated effectiveness. Therefore, this book is impossible to circumvent. Any professional who is interested in anxiety disorders should read and re-read this volume. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development and performance comparison of two different approaches for stabilizing a harmonic mode-locked fiber laser at 40 GHz

What we believe to be a new and simple approach was developed for stabilizing a harmonic mode-locked fiber laser at 40 GHz. It uses a computer to tune the modulation frequency in a 100 kHz band near 40 GHz to follow variations in the length of the optical cavity. A second approach was also developed to compare with the new approach and to draw conclusions on its performance. Results for the pulse characteristics, side-mode suppression ratio, and timing jitter show that both approaches provide an efficient way of stabilizing a harmonic FM mode-locked fiber laser.     

Grateful experiences and expressions: the role of gratitude expressions in the link between gratitude experiences and well-being

Research shows a consistent connection between the experience of gratitude and a variety of positive psychological, physical, and relational outcomes. Although this connection is largely traceable to the social meanings inherent to the experience and expression of gratitude, little is known about how such meanings are constructed via the process of communicating gratitude. In this review, we summarize the current state of knowledge on gratitude experience and expression, and examine the connection between gratitude expression and human well-being. We also propose a topography of gratitude expressions and review several issues that research on the communication of gratitude should consider in future research.     

Verification of Full-Scale Ozone Contactor Inactivation Performance Using Biodosimetry

A biodosimetric technique was used to verify the concentration-contact time (CT) values [CT10, CT integrated disinfection design framework (CT-IDDF), CT segregated flow analysis (CT-SFA)] of the ozone contactors of the DesBaillets water treatment plant (Montreal), using indigenous aerobic spore formers (ASFs) as indicators of disinfection efficiency. ASF measurement in ozonated water was performed using a large water sample concentration method. Four assays, completed over a 6-week period, involved the implementation of biodosimetric calibration curves using an ozone pilot apparatus and followed by full-scale verifications. ASF inactivation kinetics were well described by a simple Chick–Watson model. The most accurate data also indicated that the CT10 underestimates the effective CT (by 1.2–1.9-fold), whereas the CT-IDDF and CT-SFA overestimate it (by 1.0–1.7-fold and 0.9–1.5-fold, respectively). Underestimation from CT10 was more pronounced with increased ozone dose while overestimation from CT-IDDF and CT-SFA is most likely due to the difficulty in obtaining a representative ozone residual profile within the contactor. The use of segregated flow analysis provided the best estimate of disinfection performance. Biodosimetry is useful in measuring the effective CT transferred, in verifying model predictions, and in determining the influence of water quality on microbial inactivation.     

Prepartum monensin for the reduction of energy associated disease in postpartum dairy cows

A total of 1317 Holstein cows from 45 farms in the Canadian provinces of Quebec, Prince Edward Island (PEI) and Ontario were enrolled in a randomized trial during 1998 and 1999 to further confirm the efficacy of a monensin controlled release capsule in preventing periparturient disease in lactating dairy cows. Cows were randomized on the farms to receive either a monensin controlled release capsule (CRC) 2 to 4 wk before expected calving or to serve as negative controls. Health data were collected for 90 d postcalving and were analyzed with logistic regression accounting for the intraherd correlation with generalized estimating equations. Monensin CRC significantly reduced the incidence of both clinical ketosis and abomasal displacement post-calving. There was a numerical but nonsignificant decrease in the incidence of retained placenta in cows receiving a monensin CRC. A pooled analysis of two separate but similar studies (conducted in 1995 and 1998) demonstrated a strengthened association between monensin CRC administration precalving and reduced periparturient disease. A 40% reduction in both abomasal displacement and clinical ketosis was observed with precalving administration of a monensin CRC. In addition, the larger dataset highlighted a trend for a 25% reduction in the incidence of retained placenta in monensin-treated cows. Improved energy metabolism as a result of monensin treatment is likely the mechanism for the reduction in incidence of all three of these diseases. Thus the term "energy associated disease" was created to assess the combined impact of the precalving monensin treatment on the incidence of retained placenta, displaced abomasum, and clinical ketosis. The monensin controlled release capsule reduced the incidence of energy associated disease by 30%.     

Bayesian reliability: Combining information

ABSTRACT

One of the most powerful features of Bayesian analyses is the ability to combine multiple sources of information in a principled way to perform inference. This feature can be particularly valuable in assessing the reliability of systems where testing is limited. At their most basic, Bayesian methods for reliability develop informative prior distributions using expert judgment or similar systems. Appropriate models allow the incorporation of many other sources of information, including historical data, information from similar systems, and computer models. We introduce the Bayesian approach to reliability using several examples and point to open problems and areas for future work.