Some particularities of dam rehabilitation projects

The number of dams, which need rehabilitation, is growing, not only in countries that have a long tradition in dam building and operation but,also in those regions where the infrastructure is still in full development. Though rehabilitation projects generally deal with problems that are common in dam engineering practice there are some peculiarities which are a characteristic of such projects and which must be duly taken into account to avoid unsuccess and/or unnecessary costs. Regular safety inspection is essential to forestall the development of structural, hydrological and operational unsafety. if need of major repair or overall rehabilitation of a dam becomes apparent design oft he rehabilitation project must be preceded by a comprehensive checkup of the structure and appurtenant works, as well as by an evaluation of its hydrological safety inclusive of all relevant environmental aspects. The availability of complete records on the clam's structural behaviour and on meteorological and hydrological data, as well as the knowledge of the materials properties of the existing structure are important for the successful design of a rehabilitation project. To this end the installation of monitoring devices in the existing structure may be necessary to generate representative data. While the criteria to be used in structural design should correspond to current standards, the definition of hydrological design criteria depends on considerations that vary widely from region to region or even from one country to another. Some basic hydrological safety requirements, however, are recommended for general acceptance. Dam rehabilitation projects demand very careful and detailed construction planning because of their dependence on river flow conditions, operational restrictions and, often, on procedures or limitations imposed to avoid harm to the environment. of utmost importance is the timely availability of the financial funds required to complete the project, in order to avoid delays which could result in structural or operational unsafety. Since every dam sooner or later will have to undergo major repair or updating of safety, rehabilitation may evolve to a speciality of dam engineering.

Uranium speciation in groundwaters from Parana basin, Brazil

This paper describes the results of a regional study involving the sampling of 60 pumped tubular wells drilled at the Parana sedimentary basin, Brazil, which was carried out with the purpose of evaluating the U speciation in the Botucatu-Piramboia aquifer. Uranium proved to be intensively dissolved even under the enhanced reducing conditions occurring at the most confined zones of the aquifer, and Eh-pH diagrams were utilized to evaluate the influence of temperature and pressure on the migration of the U-species within the aquifer.

A second mutation in the methylenetetrahydrofolate reductase gene and the risk of venous thrombotic disease

We assessed the effect of a recently described mutation in the MTHFR gene (1298 A --> C) on the risk of deep venous thrombosis (DVT) by determining its prevalence in 190 patients with verified DVT and in age-, race- and gender-matched controls. MTHFR 1298 A --> C was found in 42.1% of patients and in 41.1% of controls. The OR for venous thrombosis was 1.07 (95% CI 0.70-1.65) for heterozygotes and 0.83 (95% CI 0.33-2.08) for homozygotes. The OR for the factor V Leiden (FVL) mutation was 3.40 (95% CI 1.22-9.48), for FII 20210 G --> A was 5.22 (95% CI 1.12-24.2) and for MTHFR 677 C --> T, 1.24 (95% CI 0.82-1.87). No significant increased risk for venous thrombosis was found when MTHFR 1298 A --> C was coinherited with FVL (OR 2.85, 95% CI 0.88-9.23), FIT 20210 G --> A (OR 7.19, 95% CT 0.87-59.4) or MTHFR 677 C --> T (OR 1.44, 95% CT 0.71-2.92). These data do not support a critical role of MTHFR 1298 A --> C in the predisposition to DVT.

Comparative wood anatomy of root and stem in Styrax camporum (Styracaceae)

Styrax camporum Pohl is a shrub common in the cerrado vegetation of south-eastern Brazil. Root and stem wood in Styrax camporum differ quantitatively and qualitatively. Quantitative differences follow normal expectations: roots have wider and longer vessel elements, a lower vessel frequency, a lower ray frequency, and wider rays. Qualitative features of the roots are: simple perforation plates, vestured pits, and septate libriform fibres; qualitative features of the stems are: multiple perforation plates, non-vestured pits, and non-septate fibre-tracheids. Based on generally accepted evolutionary trends, root wood of Styrax camporum has more specialized features than stem wood. Additional comparative studies of stem and root anatomy are needed to determine if such differences between root and stem anatomy are widespread, and consistent with the lines of specialization observed in monocotyledons.

Population dynamics of Petrochirus diogenes (Crustacea, Anomura, Diogenidae) in the Ubatuba region, São Paulo, Brazil

This work examines the population dynamics of Petrochirus diogenes in the Ubatuba region (São Paulo, Brazil), focusing on size frequency distribution, sex ratio, and reproductive and recruitment period. Collections were made with two double-rig nets in the years 1993-1996. The 799 individuals obtained were separated into 14 size classes based on the length of the cephalothoracic shield. The shield size varied from 5.4 to 40.0 mm in males and from 5.7 to 32.1 mm in females. The size frequency distribution was unimodal for both sexes. Only small oscillations occurred in the sex ratio until the seventh size class, followed by preponderance of males. This suggests a standard pattern for the sex ratio in P. diogenes. As males were found in the largest size classes, they present a clear sexual dimorphism. This characteristic can be considered as a selective advantage, mainly during the mating processes and in the agonistic behavior. Ovigerous females were recorded in the spring and summer, indicating seasonal reproduction.

Water collection by the body in a viperid snake, Bothrops moojeni

We describe a previously unreported behavior for water collection in juveniles of a neotropical viperid snake. Bothrops moojeni. When sprayed over, this snake displays a stereotyped coiling, bringing its body loops in close contact with each other, so that water is retained between the loops and over the body surface. This water is continuously ingested during and after its collection. The functional significance of the water collecting behavior is suggested to be related with the acquisition of water from short rainfalls, and with the special climatic and geologic conditions of B. moojeni habitat. Rates of evaporative water loss did not differ between juvenile and adult snakes, but since juveniles have a greater surface-to-volume ratio, they were significantly more sensitive to desiccation than the adults.

Influence of solid wastes in the mycelium growth of Lentinula edodes (berk.) Pegler

In Brazil there was little research related to Shiitake axenic culture. The aim of this research was to understand the substratum effects in the kinetics of the Shiitake mycelium growth. It was used two Shiitake strains and two different base substrate (eucalyptus sawdust and sugar cane bagasse) varying in three proportions of the supplements. The supplements, a blend of rice and wheat brans, were added in the proportion of 0, 10 and 20% of the base substrate. The experiment was composed of six treatments. The mycelium growth kinetics in volume had no effect relation to the strains and substrate and it followed a mathematical model represented by logarithmic equation. Beta, gamma and delta parameters didn't show any correlation with the growth velocity in volume. The strain L55 was better adapted than L17.

A probabilistic model for elastic-plastic fracture analysis of plane and axisymmetric structures

This work presents a methodology for elastic-plastic fracture reliability analysis of plane and axisymmetric structures. The structural reliability analysis is accomplished by means of the FORM analytical method. The virtual crack extension technique based on a direct minimization of potencial energy is utililized for the calculation of the energy release rate. Results are presented to illustrate the performance of the adopted methodology.

The tadpole of Scinax catharinae (Anura : Hylidae) with description of the internal oral morphology, and a review of the tadpoles from the Scinax catharinae group

We present a description of the external morphology and internal oral features of the tadpole of Scinax catharinae and comparisons with the known tadpoles of the S. catharinae group. Two characters of the external morphology present some intraspecific variation: the row of submarginal papillae, which can be uniseriate or absent, and the tail tip, which can be large or small, truncated or not. That said, the tadpole of S. catharinae presents some distinguishing features that differentiate it from other tadpoles in the S. catharinae group: i) the marginal row of papillae with alternate disposition, ii) the spiracle opening on the midline of the body, iii) longest snout length, and iv) largest interorbital distance. The studied species were segregated into five ecomorphological guilds, characterized by external morphological features, tadpole habitat use and vegetation formation of species range. The taxonomy of the S. catharinae group is complex, due to the morphological similarities among the adults. Larval characters could help in the resolution of the taxonomic and phylogenetic complexities, since the morphological differences among the tadpoles in this group seem more conspicuous than those found among the adults.

LARVAL DEVELOPMENT OF THE SPIDER CRAB ACANTHONYX-PETIVERII EDWARDS,H.MILNE, 1834 (DECAPODA, MAJIDAE) IN THE LABORATORY

The larval development of Acanthonyx petiverii H. M. Edwards, 1834, was studied in the laboratory through eggs hatched from ovigerous females collected in Ubatuba, state of São Paulo, Brazil. The rearings were carried out in a climatic room with constant temperature (25 degrees +/- 1 degrees C) and salinity (34,5 parts per thousand). The larvae were maintained individually and the food consisted of Artemia nauplii. The larval development of A. petiverii consists of two zoeal stages and a megalopa. All the larval stages were drawn and described in detail. Tables include those presenting morphological characters that allow the identification of zoeae and megalopa of A. petiverii. A comparative study was realized with previously studied majid species that occur in southern and southeastern Brazil.

Application of the modified Cam-Clay model to a residual soil

The modified Cam - Clay model was used to model experimental results of a saturated residual sandy soil from Sao Carlos - SP. Triaxial compression tests were performed using Bishop - Wesley cell with internal transducers to measure axial and radial strains. It was observed that the model fairly fitted experimental results, specially the principal stress difference at critical state. In general it was observed a good qualitative agreement between experimental and predicted strain values, considering compression or expansion of the samples. However, in all the stress path used, but 100 degrees and 140 degrees, the model yielded strains larger than that measured in the tests.