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Phd Thesis (Doctorat De Spécialité): Université De Ouagadougou, 1999. Dr. Mamoudou H. Dicko. Purification Et Propriétés Physico-Chimiques Des Enzymes De Curculigo Pilosa, Gladiolus Klattianus Et Boscia Senegalensis Catalysant L'Hydrolyse Des Polysaccharides (Amidon Et Béta-Glucanes), Mamoudou H. Dicko Prof. Jun 1999

Phd Thesis (Doctorat De Spécialité): Université De Ouagadougou, 1999. Dr. Mamoudou H. Dicko. Purification Et Propriétés Physico-Chimiques Des Enzymes De Curculigo Pilosa, Gladiolus Klattianus Et Boscia Senegalensis Catalysant L'Hydrolyse Des Polysaccharides (Amidon Et Béta-Glucanes), Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

The objective of this study was the research of novel and inexpensive sources of polysaccharides degrading enzymes such as amylases and glucanases from local plants in order to justify their biotechnological applications. The isolation of two l3-amylases and an endo-1,3-ß-D-glucanase was reached using common protein purification methods such as buffer extraction, ammonium sulfate fractionation, ionexchange and gel filtration chromatographies. The methods used were simple and easily reproducible, suggesting the possibilfty of large-scale production. ln the crude extract of Curculigo pilosa tuber, only ß-amylase was detected as starch degrading enzyme and its activity was approximately 282 Uig of fresh material ...


Damper For Brake Noise Reduction, Jonathan A. Wickert, Adnan Akay Jan 1999

Damper For Brake Noise Reduction, Jonathan A. Wickert, Adnan Akay

Jonathan A. Wickert

An apparatus for reducing unwanted brake noise has a ring damper affixed around a periphery of a brake rotor in a disk brake system in a manner that permits relative motion and slippage between the ring damper and the rotor when the rotor vibrates during braking. In a preferred embodiment, the ring damper is disposed in a groove formed in the periphery of the disk and is pre-loaded against the rotor both radially and transversely. The ring damper is held in place by the groove itself and by the interference pre-load or pretension between the ring damper and the disk ...


A Comparative Wear Study On Heat-Treated Aluminium-Lithium Alloy And Pure Aluminium Jan 1999

A Comparative Wear Study On Heat-Treated Aluminium-Lithium Alloy And Pure Aluminium

A.S. Md Abdul Haseeb

Wear behaviour of solution-treated and aged aluminium-lithium alloy (2.5% Li, 2% Cu, 1% Mg and 0.15% Zr) was compared with that of pure aluminium. Wear tests were carried out in ambient air in a pin-on-disc type apparatus under dry sliding conditions using hardened steel disc as the counterbody. A normal load of 10 N and a linear speed of 0.98 m s-1 were used during the tests. Microscopic investigation, microhardness measurement on the subsurface of wear scars on pins, X-ray diffraction study and morphological examination of wear debris were done to elucidate wear mechanism. It has been ...


Minimum Error Fickian Diffusion Coefficients For Mass Diffusion In Multicomponent Gas Mixtures, Shankar Subramaniam Jan 1999

Minimum Error Fickian Diffusion Coefficients For Mass Diffusion In Multicomponent Gas Mixtures, Shankar Subramaniam

Shankar Subramaniam

Mass diffusion in multicomponent gas mixtures is governed by a coupled system of linear equations for the diffusive mass fluxes in terms of thermodynamic driving forces, known as the generalized Stefan–Maxwell equation. In computations of mass diffusion in multicomponent gas mixtures, this coupling between the different components results in considerable computational overhead. Consequently, simplified diffusion models for the diffusive mass fluxes as explicit functions of the driving forces are an attractive alternative. These models can be interpreted as an approximate solution to the Stefan–Maxwell equation. Simplified diffusion models require the specification of “effective” diffusion coefficients which are usually ...