Advanced Materials Research Vol. 1098

Abstract: An important breakthrough of orthopedic surgery is to use bone cement to fill the space between an artificial joint and bone tissue, which allows the artificial joint to stabilize on human bone tissues. However, surgery failure cases due to bone cement utilization and side effects still exist at present. Therefore, the purpose of this study is to investigate bone cement characteristics, such as coagulation time, consolidation time, maximal exothermic temperature and anti-compressive strength, etc. under different mixture ratios. Our results showed that the smaller the ratio of polymethyl methacrylate and methyl methacrylate (PMMA/MMA), the lower exothermic temperature and the stronger anti-compressive resistance. These results are helpful to reduce incidences of post surgery side effects. Of note, bone cement supplement decreases corresponding to loading and operating time, which will become a major challenge for orthopedic surgery.

Abstract: This paper presents analysis of chemical and thermal processing (CTP) methods to support multi-component gas atmosphere processes and their mathematical models as objects in the automated process control system (APCS). CTP mathematical models, algorithms, interaction structures and concepts of APCS components based on a specialized electronic controller have been proposed and implemented. The system provides a time control of all the necessary gas atmosphere parameters – its composition, temperature, pressure, with the possibility of using saturating medium of up to four components. Implementation of the system will improve the service properties of processed products, reduce the rate of spoilage and the psychophysical stress of the production staff, as well as reduce the overall CTP time.

Abstract: Alkali activated concrete (AAC) are considered a promising building material. They show high strength, good durability, and good resistance to aggressive agents etc. But these good properties are controlled by the good design of the concretes. The paper presents the results which were recorded for self-compacting AACs with the water to slag ratio 0.50 - 0.52. The resistance of these concretes to Na₂SO₄, NH₄Cl and acetate acid is presented in this paper. These agents were selected because they represent agents which are present in compost or sewage.

Abstract: Under the pulse current, the lateral electromagnetic force on the shaped charge jet in the passive electromagnetic protective device is analyzed. Based on the equivalent circuit model, the current distribution model of metal plate is established according to the characteristic of current distribution proposed by Hummer. The lateral transient action model of a shaped charge jet is established based on the Biot Savart law. It is discussed in detail that the magnetic induction B_y of the shaped charge jet between two metal plates and the lateral electromagnetic force f_x on the shaped charge jet varies with time and location. B_y shows U distribution along the jet axial. Before the 37μs, f_x along the jet axial basically is M distribution; the maximum electromagnetic force appears in the distance near the site of the metal plates. After the 37μs, the lateral electromagnetic force along the jet axial basically is U distribution. Prior to 25μs, the total electromagnetic force F_x on the jet is approximately linear increase. In 25μ to 60μs, F_x maintains at a high level. The simulation result is identical with P. Appelgren’s result of static electrically-exploded conductors experiment.

Abstract: The diffusion phenomenon is widely spread in nature and bears a special importance for corrosion. Corrosion can have an impact on equipment and installation safety, from simple steel objects to nuclear reactors. As a result, it is extremely important to study corrosion and, indirectly, the phenomenon that sustains it, namely oxygen diffusion. The current paper analyses the mathematical model of diffusion based on differential equations. In this paper we use the diffusion that depends on a distance through a negative exponential function in order to explain the decrease of oxygen concentration, starting from the interface with atmosphere towards the inner layers of the oxides. The increase of the precision of the mathematical model can be done by adding new differential terms.