Reliability and tolerance comparison in water supply networks

The final publication is available at Springer via http://dx.doi.org/10.1007/s11269-010-9753-2Urban water supply is a high priority service and so looped networks are extensively used in order to considerably reduce the number of consumers affected by a failure. Looped networks may be redundant in connectivity and capacity. The concept of reliability has been introduced in an attempt to quantitatively measure the possibility of maintaining an adequate service for a given period. Numerous researchers have considered reliability as a measure of redundancy. This concept is usually implicit, but some researchers have even stated it explicitly. This paper shows why reliability cannot be considered a measure of redundancy given that branched networks can achieve high values of reliability and this would deny the fact that a looped network is more reliable than a branched network with a similar layout and size. To this end the paper discusses two quantitative indices for measuring expected network behavior: reliability and tolerance. These indices are calculated and a comparison is made between looped, branched, and mixed networks. © 2011 Springer Science+Business Media B.V.The authors wish to acknowledge the support received from project IDAWAS, DPI2009-11591, of the Directorate-General of Research at the Spanish Ministry of Education, the grant PAID-02-09 for a stay at the Universidad Politecnica de Valencia by the first author, and a grant MAEC-AECI 0000202066 awarded to the second author by the Ministerio de Asuntos Exteriores y Cooperacion of Spain. The use of English in this paper was revised by John Rawlins; and the revision was funded by the Universidad Politecnica de Valencia, Spain.Martínez-Rodríguez, JB.; Montalvo Arango, I.; Izquierdo Sebastián, J.; Pérez García, R. (2011). Reliability and tolerance comparison in water supply networks. 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Differential consumption of scleractinian and non-scleractinian coral larvae by planktivorous damselfishes

Planktivorous fishes are known to consume coral larvae due to their high nutritional value that can benefit both the individual and their progeny. However, how the consumption of coral larvae varies among coral and fish taxa, between day and night and with the density of coral larvae is not well understood. Here, we used a series of laboratory feeding assays to determine how the consumption of coral larvae by five planktivorous damselfish species (Abudefduf sexfasciatus, Amblyglyphidodon curacao, Dascyllus trimaculatus, D. reticulatus, and Chromis viridis) differed (1) between larvae of the broadcast-spawning scleractinian coral Acropora tenuis and the brooding non-scleractinian coral Heliopora coerulea when offered at a constant density (100 larvae/50 L), (2) between day and night (A. tenuis only), and (3) among larval densities (A. tenuis: 5–500 larvae/50 L; H. coerulea: 5–250 larvae/50 L). When coral larvae were offered at 100 larvae/50 L, all five fish species examined consumed A. tenuis (78–97 larvae h⁻¹) at a greater rate than H. coerulea (23–57 larvae h⁻¹), with these differences likely related to the behavior and/or pigmentation of the larvae. Consumption also varied among the fishes examined, though the differences were small when compared to differences between coral species. Consumption of A. tenuis was twofold higher at day than night likely reflecting the diurnally active feeding behavior of the fishes examined. When the density of coral larvae offered to the fishes was varied, three of five species exhibited a type II functional response (decelerating intake rate) for A. tenuis, while four out of five damselfish species exhibited a type III (sigmoidal intake rate) or type I (linear intake rate) for H. coerulea. This study demonstrates that predation by fishes contributes significantly to coral larvae mortality and that differences in consumption rates among coral species may affect the composition of coral recruits and ultimately coral assemblages

FLUORESCENCE-DIP INFRARED SPECTROSCOPY OF 2-PYRIDONE, ITS DIMER, AND WATER CLUSTERS

Author Institution: Department of Chemistry, Purdue UniversityFluorescence-dip infrared spectroscopy (FDIRS) and IR-UV hole-burning spectroscopy have been used to probe the structures and dynamics of hydrogen bonding in the $S_{0}$ and $S_{1}$ states of 2-pyridone (2PYR), its dimer $(2PYR)_{2}$, and its water-containing clusters $2PYR-(H_{2}O)_{n}$ (with $n=1$ and 2). This double resonance scheme combines the sensitivity of laser-induced fluorescence with the structure-resolving power of IR spectroscopy. 2-pyridone is the keto form of 2-hydroxypyridine (2HOP) and contains the same H-bonding sites that are found in the pyrimidine base, uracil (U). The pyridone dimer provides a first glimpse of an ``improper'' base pairing intcraction in modeling the U-U dimer. The 2-pyridone dimer is known to be a cyclic, doubly H-bonded structure with $C_{2}h$ symmetry. The infrared spectrum of this dimer has a single NH stretch which carries all the oscillator strength in this region. It produces an intense absorption with a maximum just below $2700 cm^{-}1$, and a long tail stretching nearly $200 cm^{-}1$ beyond this maximum. Distinct, sharp sub-structure with irregular spacing of about $5-10 cm^{-}1$ and widths of $2-5 cm^{-}1$ underlies this envelope. The implications of this sub-structure for the strong coupling present in the pyridone dimer will be discussed

Entropy and Multi-Objective Based Approach for Groundwater Quality Monitoring Network Assessment and Redesign

Abstract Selection of the number and location of groundwater quality monitoring wells may require the consideration of different aspects such as: monitoring objectives, temporal frequency of monitoring, and monitoring costs. These aspects were examined using observations of groundwater quality variables made twice a year in 124 wells in the northern part of the Gaza Strip, where groundwater is of the best quality. Considering these features the groundwater quality monitoring network was assessed and redesigned using entropy. The assessment procedure was based on expressing transinformation as a function of distance between wells. It was found that the number and location of groundwater quality monitoring wells varied if these aspects were embedded in the assessment and redesign procedure

Beneath 50 m of NW Pacific water: Coral reefs on the Benham Bank Seamount off the Philippine Sea

The benthic habitats on the Philippine (Benham) Rise were unknown until the joint University of the Philippines Marine Science Institute (UPMSI)/University of the Philippines Los Baños (UPLB)/Department of Agriculture-Bureau of Fisheries and Aquatic Resources (DA-BFAR) cruise of May 2014 when extensive coral reefs were discovered on the summit of the Benham Bank Seamount. Short observational surveys of five stations at depths up to 55 m revealed that the reefs were pristine and with excellent cover mostly by tiered, thick, rigid and foliose plate-forming Porites (Synaraea) rus. The voucher specimen collections indicated that there are at least 11 reef-building and two solitary coral species in the reef communities. The fish visual census and random hook-and-line fishing surveys recorded 62 species, 16 of which were reef health indicators and the rest were commercially exploited species. These short surveys yielded the first records of mesophotic coral reef biodiversity on the Benham Bank, albeit incomplete, and point to the inevitable requisite of further exploring these pristine reefs and their associated benthic habitats, since this Philippine natural heritage serves as an important area for fisheries. © 2017, University of the Philippines Los Banos. All rights reserved