Analysis of the Stability of I-Walls with Gaps between the I-Wall and the Levee Fill

Following Hurricane Katrina an extensive investigation of the performance of floodwalls in the New Orleans area was undertaken by the U. S. Army Corps of Engineers and others. This investigation included detailed study of failures of cantilevered sheet pile “I-walls” during the hurricane. An important lesson from this investigation was that gaps can form on the canal side of I-walls as the water rises in the canal and causes the I-wall to deflect. Once formed, these gaps filled with water, resulting in significantly higher loads on the walls. Gap formation was a key factor in several I-wall failures, and modeling such gaps correctly is clearly an important aspect of analyzing I-wall stability. This paper describes simple procedures for estimating the depths of gaps behind I-walls, for calculating the loads to which they are subjected, and for including them in stability analyses. The effects of gaps on the stability of the 17th Canal and the London Avenue Canal I-walls are discussed.     

A conjecture on the interface mechanics in fractures based on the interpretation of impulse vests

Time-domain tests for monitoring fracture healing, undertaken by the authors and workers elsewhere, show a repeatable characteristic signal behaviour which is difficult to explain using the linear models prevailing in biomechanics. The paper proposes a simple non-linear model which, it is believed, will reproduce the observed signal behaviour and is consistent with the biphasic stiffness model previously identified in static mechanical testing for monitoring of fracture healing. This, in turn, correlates with the two stages of callus formation in the accepted biological model.     

Popular self-help books for anxiety, depression, and trauma: How scientifically grounded and useful are they?

Self-help books for psychological disorders have become increasingly popular, yet there is surprisingly little research on their scientific status or overall utility. The authors identified 50 top-selling self-help books for anxiety, depressive, and trauma-related disorders. Using a scale derived from the literature on bibliotherapy, expert psychologists rated each book on overall usefulness, grounding in psychological science, the extent to which it offers reasonable expectations, the extent to which it offers specific guidance for implementing the self-help techniques and for monitoring treatment progress, and whether it offers potentially harmful advice. The results revealed strong intercorrelations among the scales, such that books scoring high along one dimension tended to score high along others. There was wide variability in the overall quality of the books, but several factors emerged as predictors of book quality. The most highly rated books tended to be those having a cognitive behavioral perspective, those written by mental health professionals, those written by authors holding a doctoral degree, and those focusing on specific problems. Implications of the findings, including specific recommendations for authors and consumers of self-help books, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Editorial.

In this editorial, the new editor of Psychology of Addictive Behaviors discusses the journal's history, role, scope of content, review criteria, and goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How do people really seek information about others?: Information seeking across Internet and traditional communication channels

The present research describes the manner in which individuals use various media in the interpersonal information seeking process. Stephens' (2007) information and communication technology (ICT) succession theory was applied to an interpersonal information seeking context, and hypotheses and research questions about the channels people use to seek information about others of various relationship to the seeker were offered. Two hundred and twenty-five participants responded to a survey about this topic, and they reported a greater likelihood to seek information about less-known targets using channels where they would be unidentifiable. However, participants reported a greater likelihood to seek information about more-known targets using channels where they would be identifiable. Channels such as social networking websites were frequently reported to be useful regardless of whether the target was well known or less known. Properties of these channels and their implications for interpersonal information seeking as well as theoretical implications of these findings are discussed and directions for future research are examined.     

Design of a 3-D fully depleted SOI computational RAM

We introduce a three-dimensional (3-D) processor-in-memory integrated circuit design that provides progressively increasing processing power as the number of stacked dies increases, while incurring no extra design effort or mask sets. Innovative techniques for processor/memory redundancy and fast global bus evaluation are described. The architecture can be augmented with a nearest-neighbor physical 3-D communications network that can substantially reduce interconnect lengths and relieve routing congestion. The test chip, with 128 Kb of memory and 512 processing elements (PEs) on two fully depleted silicon-on-insulator (SOI) dies, can achieve a peak of 170 billion-bit-operations per second at 400 MHz.     

The Development and Application of a Novel Optimisation Strategy for Solid Oxide Fuel Cell‐Gas Turbine Hybrid Cycles

A combined power system with solid oxide fuel cell (SOFC) and gas turbine (GT) is modelled and analysed thermodynamically in this paper. A novel optimisation strategy including the design of optimal parameters is proposed and applied to the hybrid system. Different sources of irreversible losses are specified, and entropy analyses are used to indicate the multi‐irreversibilities existing, and to assess the work potentials of the system. Expressions of the power output and efficiency for both the subsystems and the SOFC‐GT hybrid system are derived. The optimal performance characteristics are presented and discussed in detail through a parametric analysis. The developed model is expected to provide not only a convenient tool to determine the optimal system performance and component irreversibility, but also an appropriate basis to design similar complex hybrid power plants. This new approach can be further extended to other energy conversion settings and electrochemical systems. Decision makers should therefore find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems.     

Using sUAS for the Development and Validation of Surface Water Quality Models in Optically Deep Mine Waters

This study demonstrated novel remote monitoring techniques for mining-impacted surface waters using spectral data from two different platforms (multispectral sUAS and handheld hyperspectral sensors) and the feasibility of using sUAS-derived multispectral imagery to estimate in-situ metal concentrations in two passive mine drainage treatment systems. Strong linear relationships (e.g. R²_adj.?>?0.74) were found between multispectral reflectance and various in-situ constituent concentrations (e.g. Fe, Li, Mn, Pb, and Zn). Developed ordinary least squares (OLS) models estimated mean metal concentrations within 1% of the observed value and a 70% confidence interval. Validation at a separate site treating waters of a different geologic origin allowed us to assess the models’ site-specificity. Validation of some models was not possible within this study’s statistical constraints (e.g.?±?25% of the observed in-situ value). However, two models were validated and when the linear relationships were examined with site-specific spectra (i.e. sUAS-derived multispectral imagery), significant improvements to the models were observed. Employing hyperspectral remote sensing techniques yielded a novel identification procedure for optically shallow waters. This exponential relationship (e.g. R²?=?0.73) evaluates the feasibility of using remote sensing technologies to assess water quality before any model development efforts. A tool capable of identifying remote sensing interferences will be crucial for the future of environmental remote sensing. Using sUAS to estimate in-situ water quality provides a new way to monitor passive mine water treatment systems, potentially advancing the efficiency and cost-effectiveness of monitoring and altering traditional environmental remote sensing strategies.