Integration of Low-Impact Development into the International Stormwater BMP Database

Low impact development (LID) strategies are being encouraged in many communities as an approach to reduce potential adverse impacts of development on receiving streams. Many questions exist regarding how well various LID strategies perform in different settings, just as similar questions have been raised regarding performance of traditional stormwater best management practices (BMPs). Whereas historical focus on BMP performance has been water quality concentrations or loads, characterization of volume reduction benefits for both conventional and LID practices is increasingly an objective of researchers and stormwater managers. More than a decade ago, Urban Water Resources Research Council (UWRRC) members worked to develop a set of standardized monitoring and reporting protocols for traditional BMPs and to establish a master database for the purpose of evaluating BMP performance and the factors affecting performance. This effort culminated in the International Stormwater BMP Database (www.bmpdatabase.org), which contains data for more than 360 BMPs and continues to operate as a clearinghouse for stormwater BMP data and performance analyses. During 2008–2009, the International Stormwater BMP Database project expanded to better integrate LID into the database and develop a set of metrics that can be used to characterize BMP performance with regard to surface runoff volume reduction. This paper provides a condensed overview and progress report on the LID-focused effort, including the following topics: (1)?monitoring guidance for LID at the overall site development level, (2)?an overview of recent changes to the International Stormwater BMP Database to better accommodate LID studies, (3)?a summary of LID studies currently included in the database, and (4)?a proposed approach for evaluating performance of LID studies with regard to reducing surface runoff volumes.     

New line-based thinning algorithm

Thinning algorithms can be classified into two general types: sequential and parallel. Most of them peel off the boundaries until the objects have been reduced to thin lines. The process is performed iteratively, the number of iterations being approximately equal to half the maximum line width of the object. Several sequential boundary based algorithms have been proposed, but they have limitations. A new line-base algorithm is presented. the thinning element of the algorithm is a line and not, as more common, a point. The algorithm is based on a new line thinning model and is applicable to objects of general shape. The line-based thinning algorithm gives the freedom of choosing the deletion width at each iteration, and thus significantly reduces the number of iterations. The selection of the deletion width is a trade-off between speed and quality of skeletons. Experimental results are used to compare this new algorithm to other sequential algorithms and their relative performances are assessed. The new algorithm is shown to be computationally more efficient     

O-GlcNAcylation of key nuclear and cytoskeletal proteins: reciprocity with O-phosphorylation and putative roles in protein multimerization

BACKGROUND: Registered mortality from cryptogenic fibrosing alveolitis (CFA) in England and Wales has increased substantially since the specific International Classification of Diseases code for CFA was introduced in 1979. However, since a significant proportion of deaths from CFA are misclassified as post inflammatory fibrosis (PIF), it is possible that the observed rise in CFA mortality is due to diagnostic transfer from this code. To investigate this, and to assess mortality trends in other countries, annual CFA and PIF mortality data from England and Wales, USA, Australia, Scotland, Canada, New Zealand, and Germany were analysed. METHODS: Crude annual mortality rates were calculated and rates standardised by Poisson regression to allow assessment of changes over time and comparison between countries, sexes, and age groups. The relative trends in mortality from CFA and PIF were assessed by calculating the annual ratio of CFA to PIF deaths. RESULTS: Men were more likely than women to die from both CFA and PIF in all countries. The highest standardised CFA mortality rate occurred in England and Wales, and the lowest in Germany. Since 1979 mortality from CFA has increased in England and Wales, Australia, Scotland and Canada, but there was no trend in CFA mortality in New Zealand or Germany. In the USA mortality from CFA was low and has fallen. Mortality from PIF increased in all countries except New Zealand and Germany, and the highest PIF mortality, together with the greatest increase over time, was seen in the USA. Changes over time in the annual ratio of CFA to PIF deaths in all countries were small, implying that diagnostic transfer is not a major cause of the increasing CFA mortality. CONCLUSIONS: Mortality from CFA continues to increase in England and Wales and in many other countries. Diagnostic transfer from PIF does not appear to be a major cause of this.     

Interrelations of age, self-reported health, speed, and memory

Contributions of self-reported health to adult age differences in perceptual speed and memory were assessed for 301 adults ages 20-90. Participants were asked 4 health status questions, given 3 perceptual speed tests, 2 working memory tests, and 2 memory tests. Self-reported health was found to predict speed better than it predicted memory. Covariance structural equation modeling was used to assess the relations among age, self-reported health, perceptual speed, working memory, and memory. The results support the hypothesis that any effects of self-reported health on age differences in memory are mediated by perceptual speed.     

A simplified theory for the oxidative wear of steels

A simple model, based on linear oxidation, is proposed to represent oxidative wear by flaking. The theory developed predicts that log (N/ .w) varies linearly with θ⁻¹, where N is the normal applied force, .w is the wear rate per time and θ the absolute temperature of the metal substrate. The results of tests using En1A pins on N75 and En1A tracks show reasonable agreement with the theoretical predictions for θ values between 300°C and 500°C for both the N75 track and the En1A track. In these regions oxidation may reasonably be expected to constitute the majority of the wear.     

An Assessment of Surface Temperature Predictions in the High Speed Sliding of Unlubricated SAE 1113 Steel Surfaces

The paper examines the influence of temperature-dependent physical properties on the total temperatures predicted in the high-speed sliding of unlubricated SAE 1113 steel surfaces. The calculations are based on experimentally determined subsurface temperatures, friction coefficients and available temperature-dependent physical properties. It is shown that predictions based on two different asperity models are never more than 60 C different. The Jaeger-Archard theory is modified to account for differences in subsurface temperature of the two bodies. The modified theory is used to show that the predicted total temperature is relatively insensitive to differences of about 15 percent in subsurface temperature. Under these circumstances, if the subsurface temperatures are assumed equal, the predicted total temperature is the maximum value attainable.

Interpretation of the theory in the case where there are multiple junctions between the surfaces shows that for subsurface temperatures < 600 C the total temperature attained is sensitive to the number of contacts within the range 1 to 100. For a greater number of contacts or for conditions under which the subsurface temperature exceeds 600 C, there is only a small influence on the total temperature.     

73% CW power conversion efficiency at 50 W from 970 nm diode laser bars

970 nm emitting diode laser bars of broad-waveguide design have been optimised for maximum power conversion efficiency (PCE). 73% PCE at 50 W CW output power is achieved from 20% fill-factor, 1 cm diode laser bars mounted on microchannel-cooled heatsinks. The improvement is mainly the result of an increase in injection efficiency via moderately low doping of the broad-waveguide core, and reductions in operating voltage via doping optimisation of the broad-waveguide structure.     

Assembly scheduling for an integrated two-robot workcell

An assembly sequence planning scheme, giving the time optimal solution for a two-robot cell, is presented. The scheme is based on dynamic programming, and the time optimum assembly sequence is generated in two stages. In stage one, an initial candidate sequence is derived. The stage-one algorithm is computationally efficient, the complexity being O(logn/k), where n is the number of elements in k groups. It also gives near-optimal results. Expression for the lower bounds for the total assembly time are derived in order to assess the departure from optimality of the stage-one sequence. In stage two, the initial candidate sequence is optimized using an iterative technique to yield the time optimal sequence. The scheme is extended to account for precedence constraints. It can also be extended for assembly cells with more than two robots. The scheme is tested using computer simulations, and some test results are presented. For the problems solved (typically involving 20 elements), the computational times were less than 5 sec in an Apollo 300 workstation.     

Adult age differences in recall of performed and nonperformed items.

Memory for performed cognitive activities (e.g., psychometric tests of intelligence), for performed brief actions (e.g., hand wave), and for nonperformed items (e.g., written words) was assessed for 102 older and 101 younger adults. Although enactment improved recall, the beneficial effects of enactment were the same for both age groups. In fact, more than 80% of the age-related variance in memory for performed items was shared with memory for nonperformed items. Working memory and perceptual speed were important to the age differences in memory for both types of items. Performed and nonperformed items showed different serial position effects. However, the correlation between memory for the 2 types of items was high, especially for older adults, suggesting that the 2 types of memory share many common processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting job performance: Not much more than g..

The roles of general cognitive ability (g) and specific abilities or knowledge (s) were investigated as predictors of work sample job performance criteria in 7 jobs for US Air Force enlistees. Both g and s (the interaction of general ability and experience) were defined by scores on the first and subsequent principal components of the enlistment selection and classification test (the Armed Services Vocational Aptitude Battery). Multiple regression analyses, when corrected for range restriction, revealed that g was the best predictor of all criteria and that s added a statistically significant but practically small amount to predictive efficiency. These results are consistent with those of previous studies, most notably Army Project A (J. J. McHenry et al; see record 1990-27146-001). The study also extends the findings to other jobs and uses traditionally more acceptable estimates of g, application of effective sample size in cross-validation estimation, and new performance criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)