Model falsification diagnosis and sensor placement for leak detection in pressurized pipe networks

Pressurized pipe networks used for fresh-water distribution can take advantage of recent advances in sensing technologies and data-interpretation to evaluate their performance. In this paper, a leak-detection and a sensor placement methodology are proposed based on leak-scenario falsification. The approach includes modeling and measurement uncertainties during the leak detection process. The performance of the methodology proposed is tested on a full-scale water distribution network using simulated data. Findings indicate that when monitoring the flow velocity for 14 pipes over the entire network (295 pipes) leaks are circumscribed within a few potential locations. The case-study shows that a good detectability is expected for leaks of 50 L/min or more. A study of measurement configurations shows that smaller leak levels could also be detected if additional pipes are instrumented.     

Quantification of Market Performance as a Function of System Security

The tight coupling between market and system operations in the restructured environment requires a thorough understanding of the interdependence between the market performance and the way the power systems are operated. In particular, we need to go beyond the qualitative characterization and to quantify the dependence of the market performance on the system security. Such studies are typically not performed in today's regional transmission organization, or RTO, structures. In this paper, we develop a general approach to quantify the monetary impacts of complying with a specified security criterion when the deployment of appropriate preventive and/or corrective security control actions is fully taken into account. This approach is deployed in the day-ahead electricity markets and is based on the emulation of the way the RTO currently operates the market and the grid, the latter in compliance with the security criterion. The proposed approach has a wide range of applications such as comparative market performance assessments of different security criteria and the cost/benefit analysis of network improvements to mitigate the market performance impacts of a set of specified contingencies. We illustrate the application of the proposed approach on the large-scale ISO-NE system to quantify the monetary impacts associated with changing from the current security criterion to two other criteria using the actual 2005 day-ahead data-the historical system model and the bids/offers submitted-with the actual market clearing methodology. These studies capture, in a meaningful way, the impacts of the changes with respect to the current security criterion. An important finding of this study is that the economic efficiency of electricity markets need not decrease when the system is operated under a stricter criterion.     

Relation mère-enfant qualité des interactions fraternelles chez des enfants d'age préscolaire.

Assessed the degree to which the quality of the affective mother–child relationship is linked to the quality of interactions among siblings of preschool age. 44 intact families, with 2 children of which at least one was of preschool age, participated. Two evaluation methods were used: observation of relationships between siblings in semi-structured play situations at home, and a Q-sort questionnaire on the quality of the mother–child relationship. To a certain degree, there was a link between the quality of the relationship children had with their mothers and the quality of that they had with their siblings. Results indicate that the 2 kinds of intrafamilial relationships must be viewed differently for younger and older children and suggest that the relationship with the mother can contribute to the interior self- representation that could help children assert their position and play a role among siblings. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using Inductance as a Tuning Parameter for RF Meta-atoms

Nano-Micro Letters - The resonant frequency of metamaterials structured with split ring resonator (SRR) meta-atoms is determined primarily through the capacitance and inductance of the individual...     

Microswitches with sputtered Au, AuPd,Au-on-AuPt, and AuPtCu alloy electric contacts

This paper is the first to report on a new analytic model for predicting microcontact resistance and the design, fabrication, and testing of microelectromechanical systems (MEMS) metal contact switches with sputtered bimetallic (i.e., gold (Au)-on-Au-platinum (Pt), (Au-on-Au-(6.3at%)Pt)), binary alloy (i.e., Au-palladium (Pd), (Au-(3.7at%)Pd)), and ternary alloy (i.e., Au-Pt-copper (Cu), (Au-(5.0at%)Pt-(0.5at%)Cu)) electric contacts. The microswitches with bimetallic and binary alloy contacts resulted in contact resistance values between 1-2/spl Omega/. Preliminary reliability testing indicates a 3/spl times/ increase in switching lifetime when compared to microswitches with sputtered Au electric contacts. The ternary alloy exhibited approximately a 6/spl times/ increase in switch lifetime with contact resistance values ranging from approximately 0.2-1.8/spl Omega/.     

Validation de la version fran?aise du questionnaire: Coping with Children's Negative Emotions Scale--CCNES.

The purpose of this study was to measure the validity/reliability of a French version of the Coping with Children's Negative Emotions Scale--CCNES (R. A. Fabes et al., 1990). Parents (220 mothers, 154 fathers) of preschool-age children (mean age 54 mo; 111 girls, 109 boys) were presented with 12 situations in which children are likely to experience negative affects. For each situation, parents were asked to indicate how likely they would be to react in each of 6 alternative fashions (distress, punitive, encourage expression of emotion, comforting, problem-focused, and minimizing responses). Reliability (internal consistency, temporal stability) and validity findings indicate that CCNES-vf is a valid instrument to assess parental emotion-related reactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

No-load losses in transformer under overexcitation/inrush-current conditions: tests and a new model

Tests were conducted on several transformers rated at 100 kVA or less and on a power transformer rated 370 MVA in an effort to characterize the no-load losses and magnetizing resistance for transformers subjected to overexcitation and inrush current. Analysis of the results revealed that the magnetizing resistance changes as a function of the peak magnetization flux or the amplitude of the magnetic field. A new model of the instantaneous magnetizing resistance (IMR) as a function of the instantaneous flux has been developed and its dynamic use in the Electromagnetic Transients Program (EMTP) allows the form of the hysteresis cycle and the mean losses in overexcitation to be reproduced with a high degree of accuracy. The same model also accounts for losses due to the harmonics superimposed on the fundamental. The results showed that the IMR calculated under inrush current conditions is higher than that in overexcitation conditions.     

Historical Changes in the Distribution and Abundance of Constructed Ponds in Response to Changing Population Density and Land Use

In the United States most ponds are constructed for varying purposes and at varying historical rates, yet little attention is paid to their presence or ecological impact. We evaluated changes in pond density, landscape position with respect to streams, and rates of pond construction and loss within a watershed in southeastern Pennsylvania and northern Delaware that has experienced increases in population density and associated changes in land use. Based on aerial photographs taken on nine dates between 1937 and 2005, and maps prepared in 1883, abundances of all water bodies declined slightly from 1883 to 1937, then increased 18-fold during the remainder of the study period. Most ponds in 1883 (94.6%) were ‘in-line’ impoundments receiving stream inflows, whereas ‘off-line’ water bodies without inflows represented 77.3% of total ponds in 2005. Pond loss rates averaged 3.2%/year between 1883 and 1946, but declined to 0.16%/year between 1946 and 2005. Because of their changing abundance and landscape position, ponds are assuming rapidly changing ecological roles within the watershed.     

Modelling city-scale facade leaching of biocide by rainfall

A methodology is presented for estimating, at the city scale, the amount of biocide released from facades during rain events. The methodology consists of two elements. First, leaching of a single facade is simulated using a two-region model, one region for the biocide in the facade and the other for that in the flow over the facade surface. In the latter region, water advection moves the biocide to the base of the facade, and so into the environment. Rates of detachment and deposition define the exchange process between the two regions. The two-region model was calibrated on laboratory data, and afterward applied at city scale to Lausanne, Switzerland (200,000 inhabitants). The city-scale application uses the second element of the methodology, which consists of an estimate of the exposure of the city's facades to rainfall, and relating that rainfall to the over-facade flow in the calibrated single-facade model. This results in a straightforward translation of over-facade flow volume to facade paint age, a necessary connection since facade leaching is dependent on paint age. For Lausanne, it was estimated that approximately 30% of the mass of biocides applied annually is released into the environment.     

In vivo pharmacokinetic screening in cassette dosing experiments; the use of on-line Pprospekt liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry technology in drug discovery

Drug discovery is a fast growing field and the number of compounds generated daily by the pharmecutical industry is enormous. The necessity of developing new experimental strategies and analytical methods to rapidly screen the pharmacokinetics (PK) behavior of these compounds becomes a real challenge. A novel strategy to support in vivo PK screening in cassette doing experiments, using a fully automated system capable of analyzing between 320 to 960 samples a day by instrument in n-in-one experiment ( n = 64 in this work), has been developed. Using an on-line extraction technique, the average observed recovery was 64% using a single C18 procedure. A weighted (1/x) linear equation was used to perform standard calibration (0.5 to 500 ng/microL) and the average R value obtained was 0.994 (R2 = 0.997) for 63 analytes. The limit of detection, defined as a signal-to-noise ratio of 3 or greater, was found to be 25 pg for 41 of the 63 analytes (65%) and 250 pg for 57 of the 63 analytes (90%). The complete automation procedure using the Prospekt-LC-APCI/MS/MS system has substantially improved throughput in the area of drug discovery and bioanalysis.