The theories of extrusion are examined; considerable limitations exist in the analysis of extrusion conditions using either the semi-empirical approach, which is based on the assumption of homogeneous straining, or the slip-line approach. More information is required on the basic extrusion parameters such as yield stress and friction coefficient an...
The extrusion pressures determined for beryllium and mild steel over a wide range of reductions in area at temperatures between 750ºC and 1050ºC are significantly lower than those reported previously. This is attributed to better control of temperature in the work reported, the effects of container friction were assessed and the coefficient of fric...
A technique for the hot extrusion of beryllium powder within a mild steel sheath has been developed. Limitations exist with this technique in the control of extruded dimensions, particularly on complex sections or where the sheath thickness is greater than about 0.020 inch. The use of pre-consolidated powder billets is recommended to reduce the dan...
A technique for the extrusion and sintering of beryllium oxide to produce high density, fine-grained, high strength material were modified and improved. This resulted in beryllium oxide (250 p.p.m. Fe) which after extrusion and sintering for 5 hours at 1400oC in nitrogen, had an average grain size 6 pts, a mean modulus of rupture equal to 34.840 p....
Published in BBA - Biomembranes
Liposomes can be prepared by a combination of reverse phase evaporation and sequential extrusion through polycarbonate membranes. The vesicles have diameters in the range 0.05–0.5 μm and are mostly unilamellar as indicated by electron microscopy, capture volume, and availability of reactive groups to periodate oxidation. Sequential extrusion leads ...
Published in BBA - Biomembranes
A technique for the rapid production of large unilamellar vesicles by repeated extrusion under moderate pressures ( ⩽ lb/ in 2 ) of multilamellar vesicles through polycarbonate filters (100 nm pore size) is demonstrated. In combination with freeze-thaw protocols where required, this procedure results in unilamellar vesicles with diameters in the ra...
Published in American Journal of Orthodontics
Orthodontic extrusion of teeth with advanced periodontal disease was evaluated in beagle dogs. Surgical destruction of one third to one half of the attachment apparatus and the inducement of chronic periodontal disease was accomplished on the hemisected mesial roots of the mandibular premolars. The roots on one side of the mandible were extruded to...
La structure des réseaux amylacés (33 % matière sèche) obtenus à partir d'amidons de maYs normal, modifiés par différents traitments (cuissonextrusion, cylindres chauffants et empesage) a été étudiée à l'aide de diverses méthodes physico-chimiques : analyse enthalpique différentielle, diffractométrie des rayons X et susceptibilité à l'hydrolyse aci...
Après un rapide rappel sur la biomasse et son utilisation en alimentation et en "confort domestique" (textile, mobilier...), description : 1) des méthodes permettant d'utiliser les résidus industriels ou agronomiques pour fournir de l'énergie : extraction d'huile (pour en faire du carburant), densification ( pour faire des briquettes ou des produit...
