Effect of storage duration on the rheological properties of goose liquid egg products and eggshell membranes.

In practice, goose eggs are increasingly used and, therefore, the rheological properties have to be known for processing. The eggs of geese (Landes Goose, Anser anser f. domestica) were stored for one, 2, 3, 4, 6, and 8 wk at a constant temperature 4°C. First of all, the egg quality parameters were described in terms of egg weight, egg weight loss, egg shape index, yolk height, albumen height, yolk index, albumen index, and Haugh units. In the next step the rheological behavior of liquid egg products (egg yolk, albumen, and whole liquid egg) was studied using a concentric cylinder viscometer. Flow curves of all liquid egg products exhibited non-Newtonian shear thinning behavior. This behavior can be described using the Herschel-Bulkley model and for technical application using the Ostwald-de Waele model. The effect of the storage duration on the rheological behavior is different for the different liquid egg products. With the exception of very low shear rates, the viscosity of the egg yolk as well as of the whole liquid egg decreases with storage time. At lower shear rates there is a tendency toward increased albumen viscosity with storage duration. The storage duration also affects the mechanical properties of the eggshell membrane. This effect has been evaluated in terms of the ultimate tensile strength, fracture strain, and fracture toughness. All these parameters increased with the loading rate, but decreased during the egg storage. These mechanical phenomena should be respected, namely in the design of the egg model for the numerical simulation of the egg behavior under different kinds of the mechanical loading.

Effect of the loading rate on compressive properties of goose eggs.

The resistance of goose (Anser anser f. domestica) eggs to damage was determined by measuring the average rupture force, specific deformation and rupture energy during their compression at different compression speeds (0.0167, 0.167, 0.334, 1.67, 6.68 and 13.36 mm/s). Eggs have been loaded between their poles (along X axis) and in the equator plane (Z axis). The greatest amount of force required to break the eggs was required when eggs were loaded along the X axis and the least compression force was required along the Z axis. This effect of the loading orientation can be described in terms of the eggshell contour curvature. The rate sensitivity of the eggshell rupture force is higher than that observed for the Japanese quail's eggs.

[Intramedullary nailing of fractures of forearm in adults.]. / Nitrodrenové hrebování zlomenin predloktí u dospelých.

The authors present a three-year retrospective group of 32 adult patients with the diaphyseal fractures of the forearm treated surgically. Only in 3 cases a standard plate technique was used. All other surgeries were performed by intramedullary nailing using Prevot nails, strong Kirschner wires, True/Flex flexible nails and a bilaterally locked Foresight nail. Long-term results were in detail evaluated in a group of 15 patients with the implanted True/Flex nail. Minimum period of the follow-up was 6 months after operation, the average was 14,7 months. The nailing of both bones of the forearm with the use of a traction frame took on average 48 minutes. During the nailing there occurred 5 complications. Once a protruding tip of the nail was left in the region of the wrist, twice the fractured radius remained distracted, once there occurred "jamming" of the nail necessitating its shortening and once the tendon of the finger extensor was injured. No early postoperative complications were recorded. Of late complications only one case resulted in the development of a malunion in the patient who had a combination of True/Flex nail with K-wire. After the replacement of K-wire by a True/Flex nail the malunion quickly healed. We did not record any radioulnar synostosis, migration or bending of the implant or any late postoperative infection. All fractures healed. The nails were removed only in 5 cases, on average 10,2 months after the surgery. Further, the work summarizes technical conditions and surgical methods of nailing and compares individual sets of instruments and implants which are at present available. Among the advantages of the intramedullary nailing as compared to the plate technique is the miniinvasive method, shorter duration of the surgery, minimal blood loss, a small risk of infection, faster healing of fractures and a small percentage of complications. Key words: intramedullary nailing, forearm, adult.