Staging of master planning of water distribution systems using genetic algorithm optimization

Master planning of water distribution systems usually involves a long-time horizon of 25 to 50 years into the future. Estimates of future water demands are made as well as the configuration of the ultimate build-out of water distribution system. The difficulty with the results of a master planning study is that the near term needs for system expansion may not match the long-term plans. An approach of using genetic algorithm (GA) optimization for developing two master plans, one for the short term and one for the long term is presented in this paper. In addition, an approach for optimizing the staging of construction to link the short and long term master plans is also presented. This paper highlights a genetic algorithm (GA) master plan study carried out for the Barossa Valley water distribution system in South Australia. First the infrastructure needs (transmission and distribution pipelines) for 2010 were optimized using genetic algorithm optimization for the near term planning of facilities. Pipes in parallel to existing pipes and replacement pipelines were sized. New and expanded pump stations were also considered. Once the 2010 master plan was developed, a staging analysis was carried out to identify a solution to satisfy the current demands (year 2005). A master plan to satisfy year 2025 demand predictions was also developed as part of the study. In the year 2025 master plan, improvements were sized to use components that would have been used to extend the system from year 2010 to 2025.Alana M. Duncker, Angus R. Simpson, and Tomasz Woznia

Interferometry with Bose-Einstein Condensates in Microgravity

Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation of the wave nature of matter. Due to their unique coherence properties, Bose-Einstein condensates are ideal sources for an atom interferometer in extended free fall. In this paper we report on the realization of an asymmetric Mach-Zehnder interferometer operated with a Bose-Einstein condensate in microgravity. The resulting interference pattern is similar to the one in the far-field of a double-slit and shows a linear scaling with the time the wave packets expand. We employ delta-kick cooling in order to enhance the signal and extend our atom interferometer. Our experiments demonstrate the high potential of interferometers operated with quantum gases for probing the fundamental concepts of quantum mechanics and general relativity.Comment: 8 pages, 3 figures; 8 pages of supporting materia

Cube law, condition factor and weight-length relationships: history, meta-analysis and recommendations

This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W = aLb for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean = 100aLb−3. Relative weight Wrm = 100W/(amLbm) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given

Fluoroscopy usage in contemporary interventional electrophysiology: Insights from a European registry

Background: Fluoroscopy has been an essential part of every electrophysiological procedure since its inception. However, till now no clear standards regarding acceptable x-ray exposure nor recommendation how to achieve them have been proposed. Hypothesis: Current norms and quality markers required for optimal clinical routine can be identified. Methods: Centers participating in this Europe-wide multicenter, prospective registry were requested to provide characteristics of the center, operators, technical equipment as well as procedural settings of consecutive cases. Results: Twenty-five centers (72% university clinics, with a mean volume of 526 ± 348 procedures yearly) from 14 European countries provided data on 1788 cases [9% diagnostic procedures (DP), 38% atrial fibrillation (AF) ablations, 44% other supraventricular (SVT) ablations, and 9% ventricular ablations (VT)] conducted by 95 operators (89% male, 41 ± 7 years old). Mean dose area product (DAP) and time was 304 ± 608 cGy*cm2, 3.6 ± 4.8 minutes, 1937 ± 608 cGy*cm2, 15.3 ± 15.5 minutes, 805 ± 1442 cGy*cm2, 10.6 ± 10.7 minutes, and 1277 ± 1931 cGy*cm2, 10.4 ± 12.3 minutes for DP, AF, SVT, and VT ablations, respectively. Seven percent of all procedures were conducted without any use of fluoroscopy. Procedures in the lower quartile of DAP were performed more frequently by female operators (OR 1.707, 95%CI 1.257-2.318, P =.001), in higher-volume center (OR 1.001 per one additional procedure, 95%CI 1.000-1.001, P =.002), with the use of 3D-mapping system (OR 2.622, 95%CI 2.053-3.347, P &lt;.001) and monoplane x-ray system (OR 2.945, 95%CI 2.149-4.037, P &lt;.001). Conclusion: Exposure to ionizing radiation varies widely in daily practice for all procedure. Significant opportunities for harmonization of exposure toward the lower range has been identified

Catecholamine handling in the porcine heart: a microdialysis approach

Experimental findings suggest a pronounced concentration gradient of norepinephrine (NE) between the intravascular and interstitial compartments of the heart, compatible with an active neuronal reuptake (U1) and/or an endothelial barrier. Using the microdialysis technique in eight anesthetized pigs, we investigated this NE gradient, both under baseline conditions and during increments in either systemic or myocardial interstitial fluid (MIF) NE concentration. At steady state, baseline MIF NE (0.9 +/- 0.1 nmol/l) was higher than arterial NE (0.3 +/- 0.1 nmol/l) but was not different from coronary venous NE (1.5 +/- 0.3 nmol/l). Local U1 inhibition raised MIF NE concentration to 6.5 +/- 0.9 nmol/l. During intravenous NE infusions (0.6 and 1.8 nmol. kg(-1). min(-1)), the fractional removal of NE by the myocardium was 79 +/- 4% to 69 +/- 3%, depending on the infusion rate. Despite this extensive removal, the quotient of changes in MIF and arterial concentration (DeltaMIF/DeltaA ratio) for NE were only 0.10 +/- 0.02 for the lower infusion rate and 0.11 +/- 0.01 for the higher infusion rate, whereas U1 blockade caused the DeltaMIF/DeltaA ratio to rise to 0.21 +/- 0.03 and 0.36 +/- 0.05, respectively. From the differences in DeltaMIF/DeltaA ratios with and without U1 inhibition, we calculated that 67 +/- 5% of MIF NE is removed by U1. Intracoronary infusion of tyramine (154 nmol. kg(-1). min(-1)) caused a 15-fold increase in MIF NE concentration. This pronounced increase was paralleled by a comparable increase of NE in the coronary vein. We conclude that U1 and extraneuronal uptake, and not an endothelial barrier, are the principal mechanisms underlying the concentration gradient of NE between the interstitial and intravascular compartments in the porcine heart

Time Course and Mechanism of Myocardial Catecholamine Release During Transient Ischemia In Vivo

BACKGROUND: Elevated concentrations of norepinephrine (NE) have been observed in ischemic myocardium. We investigated the magnitude and mechanism of catecholamine release in the myocardial interstitial fluid (MIF) during ischemia and reperfusion in vivo through the use of microdialysis. METHODS AND RESULTS: In 9 anesthetized pigs, interstitial catecholamine concentrations were measured in the perfusion areas of the left anterior descending coronary artery (LAD) and the left circumflex coronary artery. After stabilization, the LAD was occluded for 60 minutes and reperfused for 150 minutes. During the final 30 minutes, tyramine (154 nmol. kg(-1). min(-1)) was infused into the LAD. During LAD occlusion, MIF NE concentrations in the ischemic region increased progressively from 1. 0+/-0.1 to 524+/-125 nmol/L. MIF concentrations of dopamine and epinephrine rose from 0.4+/-0.1 to 43.9+/-9.5 nmol/L and from <0.2 (detection limit) to 4.7+/-0.7 nmol/L, respectively. Local uptake-1 blockade attenuated release of all 3 catecholamines by >50%. During reperfusion, MIF catecholamine concentrations returned to baseline within 120 minutes. At that time, the tyramine-induced NE release was similar to that seen in nonischemic control animals despite massive infarction. Arterial and MIF catecholamine concentrations in the left circumflex coronary artery region remained unchanged. CONCLUSIONS: Myocardial ischemia is associated with a pronounced increase of MIF catecholamines, which is at least in part mediated by a reversed neuronal reuptake mechanism. The increase of MIF epinephrine implies a (probably neuronal) cardiac source, whereas the preserved catecholamine response to tyramine in postischemic necrotic myocardium indicates functional integrity of sympathetic nerve terminals