In order to improve bioactivity of new type of titanium alloy, TNTZ, Hydroxyapatite (HA) coating is applied. Electrophoretic Deposition (EPD) has chosen as coating method because the simplicity of the instrument and its making, inexpensive cost, and ability to coat things with complicated design. EPD used electric current to move the HA particle through electrode in the suspension of ethanol and HA. Desired HA coating quality can be adjusted with optimizing the voltage and coating time. This research aimed to analyzed the effect of voltage and coating time of EPD process toward the HA coating that produced on the surface of new type titanium implant prototype, Ti-29Nb-13Ta-4.6Zr (TNTZ). Voltages are in range of 3, 5, and 7 volt and coating times are in range of 3, 5, and 7 minutes. Based on the result it is known that the best HA coating that can be produced are on 7 minutes and 7 volt. This best result shows the good surface morphology, highest value of screw mass growth, coating thickness, and surface coverage. Enhancement of voltage will affect the surface coverage value of HA coating, however, coating time will affect the thickness. Based on this research it can be concluded that enhancement of the voltage can produced HA coating that spread more evenly that proved by the increasing of surface coverage value. The enhancement of coating time will produce thicker layer of HA coating and increase deposition rate of HA on the implant surface. This result shows that the EPD can be used to produce TNTZ titanium implant that coated with HA for orthopedic application.
Biomedical Science, Medicine Faculty, Universitas Andalas, Padang, Indonesia
Mechanical Engineering, Engineering Faculty, Universitas Andalas, Padang, Indonesia
) Biology Department, Mathematics and Science Faculty, Universitas Andalas, Padang, Indonesia
Vibration occurs due to excitation both from within and from outside the system, but the effect of vibration is very dependent on the excitation frequency and the elements of the vibration system itself. The purpose of this research is to find out the natural frequency value of the test specimens using accelerometer as a result of 2 selenoids with the same frequency as the fix-fix. The natural frequency measurement of the cylinder beam rod with fix-fix pedestal. Four points of the test were given by using a double solenoid with the same frequency given on beam rod by varying the test point, then measured using 3 accelerometer and measured data then processed using data acquisition DT8837 through Quick DAQ program. The natural frequency of the beam cylinder rod can be detected by testing by using an excitation shaker or selenoid which in the beam cylinder rod is given disturbance by giving the excitation then recorded using accelerometer then processed using the data acquisition so that the frequency value of the beam rod is obtained. It was found that the processing of vibration analysis using the FFT process is used to find the frequency components of the mixed and hidden signal by noise in the time history signal. Natural frequency value is very important to know because if not known when designing a tool if not known natural frequency will harm the tool because if the tool vibrates about the natural frequency.
Department of Mechanical Engineering, Faculty of Engineering, Universitas Riau, Indonesia
Contact with O2 and at the same time ability to absorbent of nutrient will very determining of productivity level of bakterioselulosa. On that account, for the scale up production , there are some done effort, like Rotary Disc Reactor ( RDR), as developed by Norhayati [1]. The RDR unable to rotating less than 7 rpm ( equivalent 10 second to every rotation). At this research, weakness of the rotary disk bioreaktor overcome by developing Controlled Dip Reactor, CDR. Excess of proposed appliance is user can arrange the the duration submerged phase in growth liquid medium and exposed to the air phase as according to experiment design, so that more effective and be free to to gain time optimum to each the phase utilize to get maximal production of bakterioselulosa. At the testing, designed appliance can lift place grow medium of bakterioselulosa toward as high as 15 cm meaning exposed to the air,and degrade place grow of bakterioselulosa medium downwards until 1 cm measured from medium place base, which mean bakterioselulosa submerged liquid of the growth medium and the time exposed to the air and exposed to the liquid can be controlled to vary from 1 until 20 minute.
Department of Electrical Engineering, Universitas Riau, Indonesia
