Objectives This work presents laser coating of grade 1 pure titanium (Ti) dental implant surface with sintered biological apatite beta-tricalcium phosphate (β-TCP), which has a chemical composition close to bone. Materials and methods Pulsed Nd:YAG laser of single pulse capability up to 70 J/10 ms and pulse peak power of 8 kW was used to implement the task. Laser pulse peak power, pulse duration, repetition rate and scanning speed were modulated to achieve the most homogenous, cohesive and highly adherent coat layer. Scanning electron microscopy (SEM), energy dispersive X-ray microscopy (EDX), optical microscopy and nanoindentation analyses were conducted to characterise and evaluate the microstructure, phases, modulus of elasticity of the coating layer and calcium-to-phosphate ratio and composition. Results showed that the laser power and scanning speed influenced coating adherence. The cross-sectional field-emission scanning electron microscopy images at low power and high speed showed poor adherence and improved as the laser power increased to 2 kW. Decreasing the scanning speed to 0.2 mm/s at the same power of 2 kW increased adherence. EDX results of the substrate demonstrated that the chemical composition of the coat layer did not change after processing. Moreover, the maps revealed proper distribution of Ca and P with some agglomeration on the surface. The sharp peaks on the X-ray diffraction patterns indicated that β-TCPs in the coat layer were mostly crystalline. The elastic modulus was low at the surface and increased gradually with depth to reach 19 GPa at 200 nm; this value was close to that of bone. The microhardness of the coated substrate increased by about 88%. The laser pulse energy of 8.3 J, pulse peak power of 2 kW, pulse duration of 4.3 min, repetition rate of 10 Hz and scanning speed of 0.2 ms−1 yielded the best results. Conclusion: Both processing and coating have potential use for dental implant applications.
The biomarker significance of three chemokines (CXCL8, CXCL10 and CXCL16) was evaluated in sera of 45 breast cancer (BC) and 28 benign breast lesion (BBL) patients, as well as 20 control women. Clinical stage and tumor expression of estrogen (ER), progesterone (PgR) and human epidermal growth factor receptor-2 (HER-2) receptors were considered in this evaluation. The results demonstrated that CXCL8, CXCL10 and CXCL16 showed a significant increased median in BC and BBL patients compared to control (CXCL8: 47.3 and 25.7 vs. 15.0; CXCL10: 37.6 and 30.7 vs. 13.1; CXCL16; 27.9 and 25.2 vs. 19.2 pg/ml, respectively). The increased levels of CXCL8 and CXCL16 were more pronounced in triple-negative and HER-2 positive p
... Show MoreThis study deals with the absence of state control over the whole of the Syrian geography in creating an environment conducive to the emergence of a new force represented by armed groups and organizations that point to fundamental changes in the conflict and to transform competition for control over the land into a struggle for influence. Which in itself represents the prospects of change in the Syrian scene, and that understanding their interests requires shedding light on the extent of the continuation of this competition and the conflict on land and expansion at the expense of the other, and thus contribute to complicate the Syrian scene, especially after attempts to bite Of land and annexation to each party's areas of influence, espe
... Show MoreThe food web is a crucial conceptual tool for understanding the dynamics of energy transfer in an ecosystem, as well as the feeding relationships among species within a community. It also reveals species interactions and community structure. As a result, an ecological food web system with two predators competing for prey while experiencing fear was developed and studied. The properties of the solution of the system were determined, and all potential equilibrium points were identified. The dynamic behavior in their immediate surroundings was examined both locally and globally. The system’s persistence demands were calculated, and all conceivable forms of local bifurcations were investigated. With the aid of MATLAB, a numerical simu
... Show MoreThis paper investigate a sensorless speed control of a separately excited dc motor fed from a buck type dc-dc converter. The control system is designed in digital technique by using a two dimension look-up table. The performance of the drive system was evaluated by digital simulation using Simulink toolbox of Matlab.
This research focuses on the field of theatrical production, and focuses on the semantic displacement of the sign in the visual formation of the theater show, so the research has been entitled: "The semantic displacement of the sign and the visual formation of the postmodern theater ". Its importance is to illustrate the aesthetics produced by the semantic displacement of the theatrical sign and it is specialized in postmodern theater. The purpose of the research can be delimited to revealing the aesthetic work of the semantic displacement of the sign and the visual formation in the postmodern theatre. The study temporal boundary is 2017 and the capital of Baghdad is its spatial boundaries. The research sample was "Striptease
... Show MoreAfter the twenty – first century become necessary for us motorcade era in educational a chevements by searching for the best strategies and teaching methods and techniques artotalbagesh resorting to the strategy
Did not use in use in the teaching of the foreseeable material general by voice and teaching perspective for the student of the class fourth science
In particular ,so the researcher asking the question follows:
Can the peer education strategy to have an impact in perspective drawing skill development ?
From here it demonstrated the importance of current research know the impact of p
... Show MoreIn this paper, the Monte Carlo N-Particle extended computer code (MCNP) were used to design a model of the European Sodium-cooled Fast Reactor. The multiplication factor, conversion factor, delayed neutrons fraction, doppler constant, control rod worth, sodium void worth, masses for major heavy nuclei, radial and axial power distribution at high burnup are studied. The results show that the reactor breeds fissile isotopes with a conversion ratio of 0.994 at fuel burnup 70 (GWd/T), and minor actinides are buildup inside the reactor core. The study aims to check the efficiency of the model on the calculation of the neutronic parameters of the core at high burnup.