Papers by Keyword: ACP

Abstract: Bone tissue engineering has been used in the biomedical field to treat bone defects by implanting scaffolds into bone tissue. However, the currently developed scaffold still needs to be developed to obtain scaffold building materials with good compatible properties and can regenerate damaged bone cells. This study combines PVA/Chitosan polymer with CHA of tuna bone using the porogen leaching method at a calcination temperature of 100°C for 12 hours. The purpose of this study was to determine the physicochemical properties by characterizing XRD, SEM-EDX, FTIR, and the porosity of the scaffold. The results obtained from the results of the PVA/Chitosan/CHA XRD patterns are the formation of the PVA/Chitosan phase at 2θ(°)=19.68, the IR spectrum of the 𝑃𝑂₄³⁻group band and 𝐶𝐻₂ stretching, the ratio mol Ca/P is 1.98, the pore diameter is 1.561 ± 0.07 μm and the porosity is 55.04%. These results indicate that the PVA/Chitosan/CHA scaffold is an amorphous calcium phosphate (ACP) that has the potential for bone tissue engineering.

Abstract: Composite materials are widely used in the industry for their physical and mechanical properties. The objective of this work is the characterization of some composite materials with natural fibers, in order to determine the suitability in a later use in automotive components. For this purpose, we intend to obtain a model of tensile tests using finite element software, in order to be able to dimension real components.

Abstract: Wireless network optimization is an important link in the beginning of the wireless communication network construction process, which decides the construction of wireless communication network whether scientific. This paper focuses on the method and content of the LTE wireless network optimization, mainly involves in the planning process and key technologies of LTE wireless network. First, this paper discusses LTE network parameters optimization include PCI, Cells, RS, C\N and RSC\RSRP. Then, verify the scheme scientific based on Automatic Cell Planning. Finally, through the network experiment examine the feasibility of the scheme.

Abstract: To change the status of time-consuming and over-reliance on technicians in mechanical system alignment process, the ACP technology is presented. The mapping between alignment process parameters and dynamic parameters was established through contact theory to build the agent model for parts. While the second mapping between dynamic parameters and machine dynamic characteristics is calculated by dynamic simulation software to conduct computational experiments. Experimental data is analyzed in order to implement data mine, optimize the alignment process, guide technician alignment, modify the theory mapping and improve the alignment efficiency.

Abstract: Amorphous calcium phosphate (ACP) was prepared by a sol-gel method from Ca alkoxide synthesized with Ca metal and ethanol in N2 atmosphere. As-prepared products by sol-gel method were spherical ACP particles of approximately 3 to 10 nm in diameter before heat-treatments. The results from Ca-K edge of as-synthesized ACP showed only one peak around 0.2 nm, suggesting the presence of the first neighbor of Ca in Ca-PO4 cluster.

Abstract: Our earlier studies showed that several ions inhibit the crystal growth of apatite and promote the formation of amorphous calcium phosphates (ACP). These ions include: magnesium (Mg), zinc (Zn), stannous (Sn), ferrous (Fe), carbonate (CO3), pyrophosphate (P2O7). The purpose of this study was to investigate the effect of combination of these ions (e.g., Mg & CO3, Mg & P2O7, Mg & Zn, etc) on the formation and stability of ACP. ACP compounds containing the different ions were prepared at 25 and 37oC according to the method we previously described. Chemical stability was investigated by suspending the different ACP preparations in solutions with or without inhibitory ions. Thermal stability was determined by sintering the ACP at different temperatures. Dissolution properties were determined in acidic buffer. The ACP before and after chemical or thermal treatment were analyzed using X-ray diffraction, infrared spectroscopy, and thermogravimetry. Results showed synergistic effects of inhibitory ions on the formation of ACP. ACP materials, regardless of their composition, remained amorphous even after heat treatment at 400oC. Transformation of ACP to other calcium phosphate phases depended on the pH and on the solution composition.