Search results for "97"
showing 10 items of 1081 documents
AN ANALYTICAL SOLUTION OF KINEMATIC WAVE EQUATIONS FOR OVERLAND FLOW UNDER GREEN-AMPT INFILTRATION
2010
This paper deals with the analytical solution of kinematic wave equations for overland flow occurring in an infiltrating hillslope. The infiltration process is described by the Green-Ampt model. The solution is derived only for the case of an intermediate flow regime between laminar and turbulent ones. A transitional regime can be considered a reliable flow condition when, to the laminar overland flow, is also associated the effect of the additional resistance due to raindrop impact. With reference to the simple case of an impervious hillslope, a comparison was carried out between the present solution and the non-linear storage model. Some applications of the present solution were performed…
On Randomness and Structure in Euclidean TSP Instances: A Study With Heuristic Methods
2021
Prediction of the quality of the result provided by a specific solving method is an important factor when choosing how to solve a given problem. The more accurate the prediction, the more appropriate the decision on what to choose when several solving applications are available. In this article, we study the impact of the structure of a Traveling Salesman Problem instance on the quality of the solution when using two representative heuristics: the population-based Ant Colony Optimization (ACO) and the local search Lin-Kernighan (LK) algorithm. The quality of the result for a solving method is measured by the computation accuracy, which is expressed using the percent error between its soluti…
Optimal Placement of Pressure Sensors Using Fuzzy DEMATEL-Based Sensor Influence
2020
[EN] Nowadays, optimal sensor placement (OSP) for leakage detection in water distribution networks is a lively field of research, and a challenge for water utilities in terms of network control, management, and maintenance. How many sensors to install and where to install them are crucial decisions to make for those utilities to reach a trade-off between efficiency and economy. In this paper, we address the where-to-install-them part of the OSP through the following elements: nodes' sensitivity to leakage, uncertainty of information, and redundancy through conditional entropy maximisation. We evaluate relationships among candidate sensors in a network to get a picture of the mutual influenc…
Groups with soluble minimax conjugate classes of subgroups
2008
A classical result of Neumann characterizes the groups in which each subgroup has finitely many conjugates only as central-by-finite groups. If $\mathfrak{X}$ is a class of groups, a group $G$ is said to have $\mathfrak{X}$-conjugate classes of subgroups if $G/core_G(N_G(H)) \in \mathfrak{X}$ for each subgroup $H$ of $G$. Here we study groups which have soluble minimax conjugate classes of subgroups, giving a description in terms of $G/Z(G)$. We also characterize $FC$-groups which have soluble minimax conjugate classes of subgroups.
The helminth community of the Iberian hare, Lepus granatensis (Lagomorpha: Leporidae), in the province of Granada, Spain
2014
Abstract The helminth community of the Iberian hare, Lepus granatensis, in the southern Spanish province of Granada was analysed, thorough the study of 487 individuals shot by hunters between November 1998 and October 1999. Six helminth species were found: Mosgovoyia pectinata (Cestoda); Trichostrongylus retortaeformis, Nematodiroides zembrae, Nematodirus sp., Passalurus ambiguus and Micipsella numidica (Nematoda). N. zembrae and M. pectinata (62.4 % and 17.2 %, respectively) were the only component species found. The predominance of helminth species with a direct life cycle is noteworthy. These two component species were significantly influenced by season of capture. Other factors, such as…
Intestinal helminth communities of Podarcis bocagei and Podarcis carbonelli (Sauria: Lacertidae) in NW Portugal
2006
Abstract A survey of gastrointestinal helminth communities of Podarcis bocagei and Podarcis carbonelli (Sauria: Lacertidae) from NW Portugal was conducted to determine the prevalence, intensity and diversity of intestinal parasites in these lizards. A few parasite species were found in both hosts, their prevalences, mean intensities and abundances of infection being low or very low. Low values of richness and abundance of parasite species were also found in the helminth infracommunities of individuals of both host species. These low values of parameters of infection and diversity are discussed and compared between both host species and among other Iberian lacertid lizards.
Gastrointestinal helminths found in the three freshwater turtles (Erymnochelys madagascariensis, Pelomedusa subrufa and Pelusios castanoides) from An…
2007
Abstract We conducted a survey of the presence, prevalence and diversity of gastrointestinal helminths in faecal samples and stomach contents of three turtle species, — Erymnochelys madagascariensis (Chelonia: Podocnemididae), Pelomedusa subrufa and Pelusios castanoides (Chelonia: Pelomedusidae), — from several localities in Madagascar. Four nematode species were detected: Atractis chabaudi, Camallanus chelonius, Falcaustra pelusios, and Spiroxys sp. E. madagascariensis, with all four species, had the greatest helminth diversity. A. chabaudi was the community’s core species, whereas Spiroxys sp. was a satellite species. Only two species (A. chabaudi and Spiroxys sp.) were found in P. subruf…
Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes
2011
Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between…
The helminth community of the Mediterranean mouse, Mus spretus, in a post-fire regenerated Mediterranean ecosystem
2007
Abstract The helminth community of the Mediterranean mouse, Mus spretus, was analysed in a post-fire regenerated Mediterranean ecosystem. The study was carried out in the Spanish Natural Park of the Serra Calderona and comprised a 13 year period, from the 2nd to the 14th year after a wildfire. A total of 121 host individuals was analysed, 66 mice from the burned area and 55 from the non-burned area used as control. The results show a helminth community consisting of 10 helminth species, characterised by low diversity, with Syphacia obvelata as the only dominant helminth species. The helminth infracommunity, determined by its origin of capture, burned or non-burned areas, shows some signific…
Storm Energy Flux Characterization along the Mediterranean Coast of Andalusia (Spain)
2019
This paper investigates wave climate and storm characteristics along the Mediterranean coast of Andalusia, for the period 1979&ndash