Leak Detection in Pipes by Frequency Response Method

The frequency response method is used to determine the location and rate of leakage in open loop piping systems. A steady-oscillatory flow, produced by the periodic opening and closing of a valve, is analyzed in the frequency domain by using the transfer matrix method, and a frequency response diagram at the valve is developed. For a system with leaks, this diagram has additional resonant pressure amplitude peaks (herein referred to as the secondary pressure amplitude peaks) that are lower than the resonant pressure amplitude peaks (herein called primary amplitude peaks) for the system with no leaks. Several piping systems are successfully analyzed for all practical values of the friction factor to detect and locate individual leaks of up to 0.5% of the mean discharge. The method, requiring the measurement of pressure and discharge fluctuations at only one location, has the potential to detect leaks in real-life pipe systems conveying different types of fluids, such as water, petroleum, and so on.     

Flow and water temperature simulation for habitat restoration in the Shasta River,California

Low instream flows and high water temperatures are two factors limiting survival of native salmon in California's Shasta River. This study examines the potential to improve fish habitat conditions by better managing water quantity and quality using flow and water temperature simulation to evaluate potential restoration alternatives. This analysis provides a reasonable estimate of current and potential flows and temperatures for a representative dry year (2001) in the Shasta River, California. Results suggest restoring and protecting cool spring‐fed sources provides the most benefit for native salmon species from a broad range of restoration alternatives. Implementing a combination of restoration alternatives further improves instream habitat. Results also indicate that substituting higher quality water can sometimes benefit native species without increasing environmental water allocations. This study shows the importance of focusing on the limitations of specific river systems, rather than systematically increasing instream flow as a one size fits all restoration approach. Copyright © 2009 John Wiley & Sons, Ltd.     

Eliciting information about organizational culture via laddering

Abstract. Eliciting information about organizational culture is an important part of system analysis and design. However, eliciting knowledge of this sort is difficult. Laddering is an established technique that is particularly suitable for eliciting information about goals and for eliciting explanations, which are important issues when investigating organizational culture. This paper describes the method, its strengths and limitations, its use in several case studies and its relation to other elicitation techniques. Recommendations for further work are given.     

Factor structure integrity of the Personal Attributes Questionnaire: An English–French comparison.

The Personal Attributes Questionnaire (PAQ) is one of the pre-eminent measures of gender-specific personality characteristics. To evaluate the PAQ'S viability 20 yrs after its creation, the authors assessed the dimensionality and psychometric properties of the original PAQ and a French version using samples of 637 English-speaking and French-speaking university administrators. The structure of the English form of the PAQ was supported for both women and men when the data were submitted to confirmatory analyses. Support was not as convincing for the dimensionality of the French form of the PAQ, however. Some evidence for expected differences in mean Instrumentality and Expressivity scores was found between women and men. Findings support the continued use of the English PAQ as a measure of Instrumental and Expressive personality traits. Further study of the French PAQ is recommended. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When Static Media Promote Active Learning: Annotated Illustrations Versus Narrated Animations in Multimedia Instruction.

In 4 experiments, students received a lesson consisting of computer-based animation and narration or a lesson consisting of paper-based static diagrams and text. The lessons used the same words and graphics in the paper-based and computer-based versions to explain the process of lightning formation (Experiment 1), how a toilet tank works (Experiment 2), how ocean waves work (Experiment 3), and how a car's braking system works (Experiment 4). On subsequent retention and transfer tests, the paper group performed significantly better than the computer group on 4 of 8 comparisons, and there was no significant difference on the rest. These results support the static media hypothesis, in which static illustrations with printed text reduce extraneous processing and promote germane processing as compared with narrated animations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditions and costs for renewables electricity grid connection: Examples in Europe

This paper compares conditions and costs for RES-E grid connection in selected European countries. These are Germany, the Netherlands, the United Kingdom, Sweden, Austria, Lithuania and Slovenia. Country specific case studies are presented for wind onshore and offshore, biomass and photovoltaic power systems, as based on literature reviews and stakeholder interviews. It is shown that, especially for wind offshore, the allocation of grid connection costs can form a significant barrier for the installation of new RES-E generation if the developer has to bear all such costs. If energy policy makers want to reduce the barriers for new large-scale RES-E deployment, then it is concluded that the grid connection costs should be covered by the respective grid operator. These costs may then be recouped by increasing consumer tariffs for the use of the grid.     

An FT-IR Study of NO2 Reduction in Nanocrystalline NaY Zeolite: Effect of Zeolite Crystal Size and Adsorbed Water

In this study, in situ transmission FT-IR spectroscopy was employed to investigate the selective catalytic reduction (SCR) of NO₂ in nanocrystalline NaY zeolite with a crystal size of 23 nm. Two specific aspects of this reaction were explored in this study: the importance of zeolite crystal size and the effect of water on the propylene-SCR reactions.     

Applied mineralogy of refinery slags

The techniques of process mineralogy can be effectively applied to the study of slags. By these techniques, the minerals or phases, phase chemistry, phase abundance, associations, crystalline habit, grain size, microtextures, and causes for certain metallurgical problems, such as metal losses to the slags, can be readily deduced. This case history is an example of the application of process mineralogy to the study of metal losses in a slag from a secondary copper refinery.     

Report to virtual HQ: the distributed city

This paper re-theorizes the notion of the distributed city not as the spatial alternative to nucleated centrality, but as an inevitable outcome of global information technology infrastructures. Rather than effecting the formal dispersal of significant elements, electronic distribution generates the intangible non-place of the telepresent, a development which was anticipated by modernists, but seems to be fundamentally negated by certain prominent urban thinkers today. This paper challenges and reformulates their views, showing how Jameson, Auge, Mulgan and Sorkin acknowledge the need to rethink our relationship to real and virtual environments, while Jacobs, Sennett, Davis and Baudrillard lament the destruction of urban spaces which cater for a proper public life, often attributing this to an increase in computer-mediated communication. Countering their position, this paper argues for complimentarity between real and virtual experiences and an acceptance of uncertainty as a defining characteristic of both city and cyberspace. City life as voluntary proximity instead of an urban culture of congestion necessarily arises from an engagement with new technology. This transformation requires designers, planners and architects to expand their conception of environmental design, and to grasp critically the creative possibilities which electronic communication opens up.