Classification of flow patterns in rectangular shallow reservoirs

This work focuses on the experimental classification of flow patterns in rectangular shallow reservoirs, including symmetric flows without any reattachment point to asymmetric flows with one reattachment point, two reattachment points, or two reattachment points and one detachment point. The median position and the natural variability of the reattachment lengths of asymmetric flows were measured for forty geometric and hydraulic conditions. The effects of dimensionless flow depth, Froude number, lateral expansion ratio and dimensionless length on the median reattachment lengths were analyzed. A number of regression equations were proposed. For “high” dimensionless flow depths and a Froude number of 0.20, a shape parameter was proposed for predicting the transition between symmetric and asymmetric flows. The results of this study are useful knowledge for improving current methods to predict the trapping efficiency and the preferential regions of deposition in reservoirs

Le musée, un lieu éducatif

This anthology contains essays on various aspects of museum education, by 35 members of the Special Interest Group on Education and Museums (SIGEM). Originally presented at a conference held in Montreal in 1995, the essays in this book address a wide range of issues related to the educational function of museums. Topics discussed include: educational, scientific and museological research; the value of guided tours and visual arts workshops; the question of evaluation; and relationships between museums and schools. 21 diagrams and 19 charts. 4 texts in English 31 texts in French. Circa 480 bibl. ref

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Experimental investigation of flow and deposit patterns in rectangular shallow reservoirs: preliminary analysis

peer reviewe

Inhibition of the activation reaction of Xenopus laevis eggs by the lectins WGA and SBA

International audienc

Numerical investigation of flow patterns in rectangular shallow reservoirs

The present work gives findings profitable for the person who wants to evaluate an asymmetric detach-reattach flow. In this study, the capability of a two-dimensional shallow-water numerical model to simulate the symmetric and asymmetric flows that can take place in rectangular shallow reservoirs varying the lateral expansion ratio and the dimensionless length is investigated. For a large lateral expansion ratio, the use of two protocols of simulation highlighted a high sensitivity of the simulated flow pattern to the initial condition. Comparison between simulated results and experimental data showed a good agreement for the critical shape parameter (combination of the lateral expansion ratio and the dimensionless length) between symmetric and asymmetric flows. A good agreement was also found for the value of the shorter reattachment length of asymmetric flows. For small lateral expansion ratios, the agreement was not so good. The model was used for even larger lateral expansion ratios in order to numerically extend the experimental dataset. This predictive work showed that the shape parameter, whose expression was only based on experiments carried out for small lateral expansion ratios, was also relevant for larger values. Moreover, the predicted values of the shorter reattachment length were also consistent with a regression only based on experimental results

Experimental investigation of flow pattern and sediment deposition in rectangular shallow reservoirs

peer reviewedThis work involved the experimental investigation of flow pattern, preferential regions of deposition and trap efficiency as a function of the length of rectangular shallow reservoirs. Four flow patterns were identified (from longer to shorter reservoirs): an asymmetric flow with two reattachment points, an asymmetric flow with one reattachment point, an unstable flow, and a symmetric flow without any reattachment point. Using dye visualizations, the median value and the temporal variability of the reattachment lengths were precisely measured for the asymmetric flows. For each stable flow, sediment tests with plastic particles were carried out. The regions of deposition on the bed of the reservoir were clearly a function of the flow pattern. The transition from an asymmetric flow pattern to a symmetric flow pattern was responsible for an abrupt decrease of the trap efficiency; a number of regression laws were discussed to take it into account

A novel interdisciplinary approach for building archaeology: The integration of mortar “single grain” luminescence dating into archaeological research, the example of Saint Seurin Basilica, Bordeaux

This paper deals with new strategies for dating the construction of ancient monuments, one of the most topical issues in archaeology. Our approach is demonstrated by the study of an emblematic early medieval Basilica Saint Seurin in Bordeaux whose oldest building phases have never been well-understood and dated before due to the lack of written sources and archaeological findings. We mainly focus on the analyses of mortar as an omnipresent and non-recyclable material whose making is undoubtedly contemporary to the building process. For the first time, we integrated a novel, recently validated protocol for dating historical mortar through optically stimulated luminescence using the « single grain technique » (SG-OSL) into archaeological research. The present work arises from close and continuous collaboration between archaeologists and archaeometers both in situ and during post-excavation analyses. SG-OSL dating of mortar, as the most innovative aspect of the study, was combined with mortar characterization, radiocarbon dating of charcoals and partly also with ar-chaeomagnetic and thermoluminescence dating of bricks for a cross-check of chronological data. We identified and dated several independent building phases in the crypt of the present church where mortar was the only building material preserved. By combining physical dating methods with stratigraphic constraints based on archaeological interpretations, all the findings were used to construct a chronological model that proves continuity in occupation of the site between the 5th and the 12th centuries, reflecting its high cultural and symbolic value. By the inter-connection of mortar dating by SG-OSL with archaeology and other fields of archaeometry, we set up a renewed interdisciplinary working model for building archaeology that opens interesting perspectives for the future of this research field

Classification of flow patterns in rectangular shallow reservoirs

peer reviewedThis work focuses on the experimental classification of flow patterns in rectangular shallow reservoirs, including symmetric flows without any reattachment point to asymmetric flows with one reattachment point, two reattachment points, or two reattachment points and one detachment point. The median position and the natural variability of the reattachment lengths of asymmetric flows were measured for forty geometric and hydraulic conditions. The effects of dimensionless flow depth, Froude number, lateral expansion ratio and dimensionless length on the median reattachment lengths were analyzed. A number of regression equations were proposed. For “high” dimensionless flow depths and a Froude number of 0.20, a shape parameter was proposed for predicting the transition between symmetric and asymmetric flows. The results of this study are useful knowledge for improving current methods to predict the trapping efficiency and the preferential regions of deposition in reservoirs