Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 4
items per page: 25 50 75
Sort by:

Abstract

Ore and non-ore mineralization in cracks filled with hydrocarbons in the dark grey Upper-Devonian limestone has been found in the Józefka quarry of Upper Devonian limestone and dolomite near the Górno village near Kielce at Holy Cross Mts. Poland. Hydrocarbons in the liquid form and iron and copper sulphides appears hear in the fault zone as joints filling. The wall rocks are impregnated by hydrocarbons giving them black color. Hydrocarbon impregnations appears also following the bedding planes The coexistence of ore mineralization and hydrocarbon suggests their common origin and migration from deep-seated sources, that may be the Silurian Ordovician or Lower to Middle Devonian black shales. The metallic-hydrocarbon compounds were suggested as metals carrier. Ore and non-ore mineralization in cracks filled with hydrocarbons in the dark grey Upper-Devonian limestone has been found in the Józefka quarry of Upper Devonian limestone and dolomite near the Górno village near Kielce at Holy Cross Mts. Poland. Hydrocarbons in the liquid form and iron and copper sulphides appears hear in the fault zone as joints filling. The wall rocks are spotty impregnated by hydrocarbons giving them black color. Hydrocarbon impregnations appears also following the bedding planes The coexistence of ore mineralization and hydrocarbon suggests their common origin and migration from deep-seated sources, that may be the Silurian Ordovician or Lower to Middle Devonian black shales. The metallic-hydrocarbon compounds were suggested as metals carrier.
Go to article

Abstract

In the paper, preliminary studies on formulation of a new constitutive equation of bone tissue are presented. A bone is modelled as a viscoelastic material. Thus, not only are elastic properties of the bone taken into account, but also both short-term and long-term viscoelastic properties are considered. A potential function is assumed for the bone, constant identification on the basis of experimental stress-strain curve fitting is completed and a preliminary constitutive equation is formulated. The experiments consisted of compressive tests performed on a cuboids-like bone sample of the following dimensions: 10x5x7.52 mm. The specimen was compressed along the highest dimension at the strain rates 0.016 s to the -1 and 0.00016 s to the -1. In addition to this, stress relaxation test was performed to identify long-term viscoelastic constants of bone. In the experiments, only displacement in the load direction was measured. The bone sample was extracted from a bovine femur. The form of the proposed potential function is such that it models a bone as a transversely isotropic material. For the sake of simplicity, it is assumed that the bone is incompressible. After the material constant identification the strain energy function proved to be adequate to describe bone behaviour under compressive load. Due to the fact that the function is convex, the results of the studies can be utilised in modelling of bone tissue in finite element analyses of an implant-bone system. Such analyses are very helpful in the process of a new prosthesis design as one can preoperatively verify the construction of the new implant and optimise its shape.
Go to article

Abstract

The aim of this research was to develop a composite material to be used as an elastomeric core of the artificial intervertebral disc. Two types of polyurethane composites with non-modified SiO2 and SiO2 modified NH2 group were obtained. The composites made of these materials have different filler content. The effect of modifying fillers for the structure and properties of these materials were investigated.
Go to article

This page uses 'cookies'. Learn more