Characteristic Drying Curves of Cocoa Beans

The characteristic drying curves of cocoa beans are determined by using a tunnel drier where conditioned air passes a single cocoa berm suspended from an electronic balance in the test section. Weight loss, and temperatures of air, testa and nib of the cocoa bean is monitored on personal computers. The nornmalised drying rate versus the normalised moisture content is regressed by least square method to fit a new polynomial model for the penetration falling rate period and a linear model for the regular regime falling rate period. It can be concluded that there are three drying periods for cocoa beans namely the constant drying rate period, the penetration falling rate period and the regular regime falling rate period. The polynomial model estimates the penetration period quite well whereas the linear model estimates the regular regime quite well as well. There is no observable influence of relative humidity and air temperature on the characteristic drying curve of cocoa beans. However, the air velocity seems to have some influence on the curve.     

Synthesis and Structural Characterization of New Lead(II) Discrete and Infinite Cage-Like Framework: A Precursor to Produce Pure Phase Nano-Sized Lead(II) Oxide

A novel Pb(II) complex, {[Pb₂(tpmba)₂(NO₃)₄]·MeOH} _n (1), was obtained by the reaction of a tripodal ligand, N,N′,N″-tris(pyrid-3-ylmethyl)-1,3,5-benzenetricarboxamide (tpmba), with Pb(NO₃)₂. The structure of complex was determined by X-ray crystallography. The results of structural analysis of the complex reveal that 1 is a M₂L₂ cage-like with a methanol molecule beside the cage. An entirely different structure and topology between 1 and similar complexes indicate that the nature of organic ligands affects the structure of assemblies. The results indicate that the framework of this complex is predominated by the nature of the organic ligand, anions, solvent and geometric need of the metal ions. It was found that the coordination number of Pb^II ions is eight, (PbN₃O₅) has a stereo-chemically active electron lone pair and the coordination sphere is hemi-directed. PbO nanoparticles are obtained by thermolysis of 1 at 180 °C with oleic acid as a surfactant. Scanning electron microscopy shows that the size of the PbO particles is ~30 nm.     

Rapport: Résultats d'essais de résistance mécanique sur échantillon de terre comprimée

Brief english summary During the last meeting of TC EBM in Marrakech in September 1995, the Public Laboratory For Tests and Studies of Morocco was committed to carrying out compression and traction tests on cement-stabilised compressed earth bricks and cylindrical samples. Such tests were also carried out by the Geomaterial Laboratory of the ENTPE in France, which is member of TC EBM. The results of these tests are presented in this paper with the aim of validating those already obtained by the ENTPE. A suitable earth material was selected to undertake this research project. Before proceeding with the cement stabilization process, organic, sulphate and chloride contents were determined. Samples were manufactured using a hydraulic machine and a specially designed steel mould. The production parameters of the cylindrical samples were the optimum water content and the static compact dry density. Other samples were obtained by assembling two halves of sawed compressed-earth bricks using the same production parameters. Curing conditions were the same for all samples before undertaking the tests. The strengths obtained were compared to those specified by the document “Proposal of standards for testing compressed earth”, which was given to the TC EBM Secretary during the September 1995 meeting in Marrakech.

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Membres du T. C.: Président: A Hakimi, Maroc;Secrétariat: N. Yamani, Maroc; M. El Korbl; Maroc;Membres; N. P. Barbosa, Brésil; E. H. Bartali, Maroc; A. Cherrabi, Maroc; P. Déncause, Maroc, Z. El Gharbi, France; A. Misra Maroc; A. Mesbah, France; M. Olivier France     

Un test d'humidification-séchage pour les blocs de terre comprimée et stabilisée au ciment

English Summary A method to characterise the durability of the cement-stabilised compressed earth blocks which TC 164-EBM is committed to developing is described in a report [1] presented at the 49th Technical Session of the RILEM General Council. The objective is to develop a wetting-drying test on cylindrical cement-stabilised compressed earth samples to determine the decrease in their compressive strength. This artificial ageing test is defined by three parameters: the duration of immersion, the duration of drying and the number of cycles. For the experimental approach to these three parameters, this method anticipates a study of the evolution of the compressive strength of 2 series of cylindrical samples having different strengths after curing, according to the duration of immersion, the duration of drying and the number of cycles. This report presents results for the constants: drying temperature (70°C) and relative humidity (40%).

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Membres du TC: Président: A. Hakimi, Maroc;Secrétariat: M. El Kortbi, Maroc; N. Yamani, Maroc;Membres: A, Acharhabi, Maroc; M. Ayeb, Maroc; N. P. Barbosa, Brésil; E. H. Bartali, Maroc; R. Bouqarfacha, Maroc; A. Cherrabi, Maroc; P. Dencause, Maroc; S. El Amine, Maroc; Z. El Charbi, France; A. Gilibert, Italie; S. Jalali, Portugal; A. Labib, Maroc; A. Lahbabi, Maroc; M. Martin, Burkina Faso; R. Mattone, Italie; A. Mesbah, France; M. Olivier, France; H. Ouissi, Maroc; B. Pignal, France; S. Sanfo, Burkina Faso; Z. Sekkat, Maroc; A. Thiombiano, Burkina Faso.

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Les résultats présentés dans ce rapport ont été discutés lors des 4e et 5e réunions du TC 164-EBM.     

Wind environment at a roof-mounted wind turbine on a peaked roof building

Knowledge of the wind resource above peaked roofs is necessary to determine whether installing small wind turbines on low-rise peaked roof buildings is feasible. The wind characteristics at a representative peaked roof barn in southern Ontario, Canada were investigated using a boundary layer wind tunnel and computational fluid dynamics. Field measurements at the barn were collected using sonic anemometers and compared with the simulation results. Wind speed amplification was confined to a region immediately above the roof and was relatively low for wind energy purposes. The presence of nearby trees or buildings adversely impacted wind speed amplification. Considering only wind-related factors, the placing of micro-wind turbines on roof peaks may be warranted. However, if sufficient space is available, it is recommended to place small turbines on a tower rather than on the peaked roof of a low-rise building.     

Tenocyte proliferation on collagen scaffolds protects against degradation and improves scaffold properties

Tissue engineering scaffolds encourage cell proliferation whilst degrading to facilitate tissue regeneration. Their mechanical properties therefore change, decreasing due to scaffold degradation and increasing due to extracellular matrix deposition. This work compares the changing properties of collagen scaffolds incubated in culture medium, with and without human tenocytes, in order to investigate the relationship between degradation and tenocyte proliferation. The material properties of scaffolds are compared over 26 days using mechanical testing, differential scanning calorimetry, infra-red spectroscopy, and histology and biochemical assays. For medium-only scaffolds, the mechanical properties decrease rapidly, while culture medium sulfhydryl content increases significantly, with no significant changes in the denaturation temperature of scaffold collagen content. Conversely, the mechanical properties and collagen content of tenocyte-seeded scaffolds increase significantly while culture medium sulfhydryl content decreases and denaturation temperature remains the same. These results indicate that tenocytes proliferation both reduces the degradation of collagen scaffolds incubated in culture medium and produces scaffolds with improved properties.     

ORGANIC GEOCHEMISTRY,BURIAL HISTORY AND HYDROCARBON GENERATION MODELLING OF THE UPPER JURASSIC MADBI FORMATION,MASILA BASIN,YEMEN

The Masila Basin is an important hydrocarbon province in Yemen but the origin of its hydrocarbons is not fully understood. In this study, we evaluate Upper Jurassic source rocks in the Madbi Formation and assess the results of basin modelling in order to improve our understanding of burial history and hydrocarbon generation. This source rock has generated commercial volumes of hydrocarbons which migrated into Jurassic and Lower Cretaceous reservoir rocks. Cuttings samples of shales from the Upper Jurassic Madbi Formation from boreholes in the centre-west of the Masila Basin were analysed using organic geochemistry (Rock-Eval pyrolysis, extract analysis) and organic petrology. The shales generally contain more than 2.0 wt % TOC and have very good to excellent hydrocarbon potential. Kerogen is predominantly algal Type II with minor Type I. Thermal maturity of the organic matter is R_r 0.69–0.91%. Thermal and burial history models indicate that the Madbi Formation source rock entered the early-mature to mature stage in the Late Cretaceous to Early Tertiary. Hydrocarbon generation began in the Late Cretaceous, reaching maximum rates during the Early Tertiary. Cretaceous subsidence had only a minor influence on source rock maturation and OM transformation.