Application of Laplace Transformation to the Analysis of an Underground Circular Cylindrical Reservoir

Analysis of underground circular cylindrical shell is carried out in this work. The forth order differential equation of equilibrium, comparable to that of beam on elastic foundation, was derived from static principles on the assumptions of P. L Pasternak. Laplace transformation was used to solve the governing differential equation at critical condition. The Greenwich contour formula was successfully used to determine the inverse transform of the obtained subsidiary equation. The final solution was found to agree with that obtained using the classical method. The Laplace transformation appeared to be less tedious and more time saving than the classical method in the solution of the aforementioned differential equation

Static Analysis of Circular Cylindrical Shell Under Hydrostatic and Ring Forces

Analysis of circular cylindrical shell under the action of hydrostatic and stiffening ring forces is carried out in this work. The differential equation of equilibrium, similar to that of beam on elastic foundation, was obtained from static principles on the assumptions of P. L. Pasternak. The initial value method was used to solve the obtained fourth order differential equation for both cases of hydrostatic and ring forces. Combined actions of hydrostatic and ring forces were studied as the location of the ring was varied along the height of the reservoir. It appears that the most favourable location for the ring is 2/3 of its height measured from the top. Bending mo-ment, shear force and hoop tension diagrams, essentially necessary for design of the reservoir, were plotted under the action of these forces.Keywords: Static analysis, cylindrical shell, hydrostatic forces, reservoir, initial value

Evaluation of structure and natural regeneration status of woody plant species in sudanian domain : Case of eastern part of National Park of Sena Oura, Chad

Many scientific studies confirmed that plants have an important ecological role maintaining the productivity of the environment and regulating the global climate. In order to valorize the wild phytogenetic resources for the efficient in situconservation and sustainable use in Sudano-zambezian region, a study was carried out in Sudanian domainprovidingquantitative informations on the community structure and natural regeneration status of woody plant species.The study site is the eastern part of National Park of Sena Oura in Chad. Adults plants (trees and shrubs) were systématically collected in 10 linear transects (20 m x 1000 m). Juvenile plants (saplings and seedlings) weresystematically collected within 40 plots (20 m × 20 m). These plots were randomly stablished in the transects, at a rate of four plots per transect.In total, 84 adults plants species grouped in 58 genera and 29 families and 66 juvenile plants species grouped in 45 genera and 27 families were inventoried. Bell andreverse J-shaped patterns of selected woody species were identified.The stand regeneration status wasgood.The stand regeneration rate were SRR = 52.29% and Hymenocardia acida (SIR = 17.95%), Combretum collinum (SIR = 14.12%), Annona Senegalensis (SIR = 6.67%) and Isoberlinia doka (SIR = 6.22%) had the most important specific index of regeneration. The specific structures showed that the structure of the total stand is the result of the dynamics of all species and their interactions.The global stand regeneration status was good.The obtained results provided quantitative informations on the community structure and natural regeneration status of woody plant species for the efficient conservation and sustainable use

Behavior of cereal’s varieties in the presence of Heterodera avenae woll (heteroderidae, tylenchida) cyst nematode in Tiaret Area (Algeria)

The behaviour of cereals varieties (Ofanto, Waha and Vitron for durum wheat; Anza and HD1120 for bread wheat and Saida with Acsad for barly) were tested towards Heterodera avenae. The analysis of the variance reveals that the nematode has an effect on the development of durum wheat for the number of ear per seedling and the weight of thousand seeds, with respectively: P = 0, 0033 and P = 0,000, for the infested varieties and the witnesses. Common wheat shows a highly significant difference (P= 0, 0000) for the varieties infested and pilot and of the same for the barley, but with a significant difference with: P= 0,0002, between the varieties of barley. The two varieties of barley were different when with the weight from 1000grains. The ACP of any species confers that Saida is the most sensitive variety followed by Ofanto and Anza to attack of this nematode.Keywords: Nematode; Heterodera; cereals; varieties; behaviou

Caractérisation physico-chimique du gypse de Tahoua

Le Gypse rencontré dans la région de Tahoua se présente sous trois formes : fibreux, nodulaire et en plaquette. Les gypses nodulaire et fibreux font l’objet de ce travail. La diffraction des rayons X (DRX) montre que l’échantillon fibreux est du gypse presque pur mais que le nodulaire contient une proportion importante d’impuretés. L’analyse chimique par ICP-AES a permis de déterminer le pourcentage de gypse (CaSO4, 2H2O) dans chaque échantillon: soit 98,44% dans le fibreux et 68,40% dans le nodulaire. L’analyse par ICP-MS avec une sensibilité de l’appareil de l’ordre du ppb, a montré que les éléments chimiques suivants: B, Sc, V, Cr, Mn, Co, Ni, Cu, Ga, As, Se, Br, Rb, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Th et U sont à des concentrations inférieures à 1μg/Kg dans chaque échantillon. Les isothermes d’adsorption et de désorption de l’azote par le gypse fibreux montrent que la surface spécifique et le volume poreux de l'échantillon sont respectivement de 21 m²/g et de 0,03 cm3/g. Les analyses ATG-ATD des gypses fibreux et nodulaire révèlent une perte en masse respectivement de 20% et 17% à 138 °C.Mots clés: Gypse, analyse, minéralogie, ea

Structure et dynamique de la végétation ligneuse juvénile issue de la régénération naturelle assistée (RNA) dans le Centre-Sud du Niger

La présente étude est conduite dans les régions de Maradi et Zinder situées dans la bande Sud du Niger où la pratique de la régénération naturelle assistée (RNA) a pris de l’ampleur depuis la fin des années 1980. Cette pratique qui consiste à entretenir les rejets a permis de régénérer lecouvert végétal et d’augmenter le rendement des cultures pluviales. Le but de ce travail est d’étudier la structure et la dynamique de la végétation ligneuse juvénile issue de la régénération naturelle assistée. Tous les individus juvéniles dont le diamètre était inférieur à 4 cm ont été comptés dans des placettes de 2000 m² suivant un transect perpendiculaire. L’importance écologique des espèces a été appréciée à partir de l’Indice de Valeur d’Importance (IVI). Les résultats révèlent que la flore juvénile de l’ensemble des sites renferme 38 espèces ligneuses réparties dans 22 familles. Les familles les mieux représentées sont les Mimosaceae (20,73%). La strate juvénile dans l’ensemble a une dynamique  déséquilibrée. En effet, très peu d’espèces ont une assez bonne  rejuvénilisation. De nombreuses espèces quasi absentes de la population juvénile méritent de bénéficier d’une attention particulière afin de minimiser la perte de phytodiversité.Mots clés : Importance écologique, juvénile, flore, phytodiversité, rejuvénilisatio

Over-reliance on English hinders cognitive science

English is the dominant language in the study of human cognition and behavior: the individuals studied by cognitive scientists, as well as most of the scientists themselves, are frequently English speakers. However, English differs from other languages in ways that have consequences for the whole of the cognitive sciences, reaching far beyond the study of language itself. Here, we review an emerging body of evidence that highlights how the particular characteristics of English and the linguistic habits of English speakers bias the field by both warping research programs (e.g., overemphasizing features and mechanisms present in English over others) and overgeneralizing observations from English speakers’ behaviors, brains, and cognition to our entire species. We propose mitigating strategies that could help avoid some of these pitfalls

Tillaberi Slaughterhouse Discharges And Their Impact On The Niger River: A Physicochemical And Microbiological Analysis

The main objective of this work was to study the solid and liquid waste discharges of the slaughterhouse of the city of Tillabéri, and their impacts on the Niger River. To do so, the identification and quantification of the solid waste of the slaughterhouse were carried out in the first step, then the physical, chemical, and microbiological characterization of the liquid discharges of the slaughterhouse and of the river water in the second step. The results obtained showed that the slaughterhouse in the urban commune of Tillabéri produced an average of 156.1 ± 41.1 kg of solid waste per day, divided into four groups: 133 kg of stercoral, 19.7 kg of seized organs, 1.9 kg of plastic and 1.4 kg of skin pieces. The average values obtained after physic-chemical and microbiological characterization of the liquid waste are as follows pH (7.08 ± 0.15), Temperature (28.6 ± 0.49), Electrical conductivity (985 ±184.1 µS/cm), COD (12860 ± 3831.8mg/l), BOD (5338 ± 1572.05mg/l), Suspended Solid (835 ± 258.7mg/l) Cl- (81.5 ± 1.3 mg/l), NO3- (0.66 ± 0.97mg/l). The BOD5/COD ratio is about 0.41. After microbiological characterization of these liquid discharges, (3.1.104 cfu) of E. coli, (3.104 cfu) of fecal coliforms, and (6.1.108 cfu) of total coliforms were found. The physicochemical and microbiological characterization of the river water showed that most of the physicochemical parameters comply with the WHO limits, except for BOD5 and COD, which have fairly high average values of (62.5 ± 47.06mg/l) and (200 ± 110.1mg/l) respectively. The E. coli found are of the order of 5.6.104 cfu, however, there are no fecal coliforms in these waters. All these values indicate that the river water is polluted. This pollution would come from the discharges of the slaughterhouse

Crowdsourcing Linked Data on listening experiences through reuse and enhancement of library data

Research has approached the practice of musical reception in a multitude of ways, such as the analysis of professional critique, sales figures and psychological processes activated by the act of listening. Studies in the Humanities, on the other hand, have been hindered by the lack of structured evidence of actual experiences of listening as reported by the listeners themselves, a concern that was voiced since the early Web era. It was however assumed that such evidence existed, albeit in pure textual form, but could not be leveraged until it was digitised and aggregated. The Listening Experience Database (LED) responds to this research need by providing a centralised hub for evidence of listening in the literature. Not only does LED support search and reuse across nearly 10,000 records, but it also provides machine-readable structured data of the knowledge around the contexts of listening. To take advantage of the mass of formal knowledge that already exists on the Web concerning these contexts, the entire framework adopts Linked Data principles and technologies. This also allows LED to directly reuse open data from the British Library for the source documentation that is already published. Reused data are re-published as open data with enhancements obtained by expanding over the model of the original data, such as the partitioning of published books and collections into individual stand-alone documents. The database was populated through crowdsourcing and seamlessly incorporates data reuse from the very early data entry phases. As the sources of the evidence often contain vague, fragmentary of uncertain information, facilities were put in place to generate structured data out of such fuzziness. Alongside elaborating on these functionalities, this article provides insights into the most recent features of the latest instalment of the dataset and portal, such as the interlinking with the MusicBrainz database, the relaxation of geographical input constraints through text mining, and the plotting of key locations in an interactive geographical browser