Wavespeed measurement in buried water distribution pipes and its significance in leak location

To determine the location of leaks in buried water pipes, acoustic methods are often used. These have proven to be very effective in metallic pipes but have been problematic in modern plastic pipes. In this paper the reason why this is so is discussed together with some measurements that were made on a bespoke test rig built by South Staffs Water plc. A particular problem is the estimate of the wavespeed. Tables are frequently used for this purpose, but these are often inaccurate and this means that a leak cannot be located accurately. An in-situ measure of the wavespeed is thus preferable. In this paper it is shown that there are significant issues in obtaining an accurate estimate of the wavespeed when a leak is present in the system. A method is proposed that overcomes some of these problems, which is discussed and is demonstrated using some data from the bespoke test-rig. © (2013) Trans Tech Publications.

Posição e densidade dos zeros de Yang-Lee do modelo de Blume-Emery-Griffiths unidimensional sobre anéis conexos e desconexos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Teorema de Sturm e zeros de polinômios ortogonais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Monotonicidade de zeros de polinômios ortogonais clássicos

Pós-graduação em Matematica Aplicada e Computacional - FCT

Zeros de Polinômios Perturbados

Pós-graduação em Matematica Aplicada e Computacional - FCT

An assessment of the economic and social impacts of climate change on the water sector in the Caribbean

The Caribbean is not homogenous with regard to water resources. The Caribbean climate can be characterized as tropical rainy, with two well-defined seasons, one, rainy, and another, less rainy: these characteristics have specificities according to the geographical location of each country. The rainy, tropical character of the Caribbean climate may suggest that there are enough water resources to satisfy life requirements. Notwithstanding, the availability and distribution of water depends on geological and geographical factors that—given the insular character and characteristics of each country—make water resources both vulnerable and limited.

Facies analysis of the Codó formation (Late Aptian) in the Grajaú area, Southern São Luís-Grajaú Basin

Facies descriptions of the Codó Formation in the Grajaú area are provided for the first time, and its sedimentary characteristics compared to those from the Codó area to allow paleoenvironmental reconstructions. Deposits in the Grajaú area include evaporites, limestones and argillites bearing features indicative of a shallow, low energy, subaqueous, saline environment exposed to meteoric and/or capillary conditions. Floodingevaporative concentration-desiccation cycles suggest a saline pan complex surrounded by extensive evaporitic mudflats. The location of the system, whether coastal or inland, is a matter open for debate. However, the later hypothesis is favored considering: 1. Sr isotopic data, with values higher than those expected for Late Aptian marine waters; 2. calcitic composition of limestones (instead of dolomitic and/or magnesitic as expected in coastal settings); and 3. presence of continental ostracods and lack of marine fauna. This interpretation is consistent with that proposed for UpperAptian deposits of the Codó area, but the depositional system there was one dominated by more stable, well-stratified, anoxic waters and evaporite precipitation in central lacustrine areas, while in the Grajaú area the salt pan was more oxygenated and ephemeral, with salt precipitation mainly in marginal areas or along surrounding mudflats.

Chromosomal diversity in three species of electric fish (Apteronotidae, Gymnotiformes) from the Amazon Basin

Cytogenetic studies were carried out on samples of Parapteronotus hasemani, Sternarchogiton preto and Sternarchorhamphus muelleri (Apteronotidae, Gymnotiformes) from the Amazon basin. The first two species exhibited both a 2n = 52 karyotype, but differed in their karyotypic formulae, distribution of constitutive heterochromatin, and chromosomal location of the NOR. The third species, Sternarchorhamphus muelleri, was found to have a 2n = 32 karyotype. In all three species the DAPI and chromomycin A3 staining results were consistent with the C-banding results and nucleolar organizer region (NOR) localization. The 18S rDNA probe confirmed that there was only one pair of ribosomal DNA cistron bearers per species. The telomeric probe did not reveal interstitial telomeric sequences (ITS). The karyotypic differences among these species can be used for taxonomic identification. These data will be useful in future studies of these fishes and help understanding the phylogenetic relationships and chromosomal evolution of the Apteronotidae.

Scattered organization of the histone multigene family and transposable elements in Synbranchus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dynamical evolution of V-type asteroids in the central main belt

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physiological Parameters in Neonatal Lambs of the Bergamasca Breed

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure and post-translational modifications of the web silk protein spidroin-1 from Nephila spiders

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Using Proteomic Strategies for Sequencing and Post-Translational Modifications Assignment of Antigen-5, a Major Allergen from the Venom of the Social Wasp Polybia paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Progesterone as a morphological regulatory factor of the male and female gerbil prostate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First cytogenetic characterization of the giant Amazonian catfish Brachyplatystoma filamentosum (Siluriformes, Pimelodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)