Phosphate solubilizing bacteria and their role in plant growth promotion

A review of stimuli-responsive shape memory polymer composites

http://ieeexplore.ieee.org/iel5/5/31047/01444179.pdf

Fundamentals of acoustics

Electrical discharge machining (EDM) is one of the earliest non-traditional machining processes. EDM process is based on thermoelectric energy between the work piece and an electrode. A pulse discharge occurs in a small gap between the work piece and the electrode and removes the unwanted material from the parent metal through melting and vaporising. The electrode and the work piece must have electrical conductivity in order to generate the spark. There are various types of products which can be produced using EDM such as dies and moulds. Parts of aerospace, automotive industry and surgical components can be finished by EDM. This paper reviews the research trends in EDM on ultrasonic vibration, dry EDM machining, EDM with powder additives, EDM in water and modeling technique in predicting EDM performances.

A review on current research trends in electrical discharge machining (EDM)

Phosphorus is an important plant nutrient which is in short supply in many agricultural soils Because much of the soluble phosphate (P) applied to soils as fertilizer is “fixed” by the soil and rendered less available to plants, the long-term application of P fertilizers has resulted in an accumulation of total soil P, most of which is poorly soluble Many soil fungi, predominantly of the genera Aspergillus and Penicillium , have been shown to possess the ability to solubilize sparingly soluble phosphates in vitro by secreting inorganic or organic acids Growth promotion and increased uptake of P by plants inoculated with P-solubilizing fungi have also been reported by many investigators

Growth Promotion of Plants Inoculated with Phosphate-Solubilizing Fungi

The increasing number of people who underwent both hip implant surgery based on World Health Organization (WHO) has received massive attention from researchers lately to develop various types of hip simulators in order to test the hip implant. Various number of hip simulator have been developed with different functions and capabilities. This paper presents the design development of biped hip simulator using SolidWorks software by taking into consideration some improvement and modifications. The finite element method is used to test the design whether it is safe to be used or not. The biped hip simulator has been successfully designed and ready to be fabricated as the endurance testing shown a positive results. The von Mises stress induced in the material is an alloy steel which is 2,975,862.3 N/m2 lower than the yield strength. Thus, the design is safe to be used as it obey the safety criterion.

https://iopscience.iop.org/article/10.1088/1742-6596/908/1/012060/pdf

Design of biped hip simulator using SolidWorks

Sliding motion for hard on soft (HOS) implant material application causes sliding impact failure. This research was conducted using diffe rent cup surfaces. Different amount pits fused on the hemispherical cup have shown the potential for improving the tribology of HoS sliding contact. Four - ball machine has been used as screening machine to evaluate the friction. The results showed that modi fied hemispherical cup with pits and lubricated with palm oil had a significant to reduce frictional rate. This new surface improvement will prolong the life span of soft implant material due to lubrication activities in HoS contact sliding.

An investigation of hard-on-soft contact: for reducing friction in hemispherical cup

Severe movement or motor disability diseases such as amyotrophic lateral sclerosis (ALS), cerebral palsy (CB), and muscular dystrophy (MD) are types of diseases which lead to the total of function loss of body parts, usually limbs. Patient with an extreme motor impairment might suffers a locked-in state, resulting in the difficulty to perform any physical movements. These diseases are commonly being treated by a specific rehabilitation procedure with prescribed medication. However, the recovery process is time-consuming through such treatments. To overcome these issues, Brain-Computer Interface system is introduced in which one of its modalities is to translate thought via electroencephalography (EEG) signals by the user and generating desired output directly to an external artificial control device or human augmentation. Here, phase synchronization is implemented to complement the BCI system by analyzing the phase stability between two input signals. The motor imagery-based experiment involved ten healthy subjects aged from 24 to 30 years old with balanced numbers between male and female. Two aforementioned input signals are the respective reference data and the real time data were measured by using phase stability technique by indicating values range from 0 (least stable) to 1 (most stable). Prior to that, feature extraction was utilized by applying continuous wavelet transform (CWT) to quantify significant features on the basis of motor imagery experiment which are right and left imaginations. The technique was able to segregate different classes of motor imagery task based on classification accuracy. This study affirmed the approach’s ability to achieve high accuracy output measurements.

/pdf/brain-computer-interface-algorithm-based-on-wavelet-phase-3yjfubgbz7.pdf

Brain-computer interface algorithm based on wavelet-phase stability analysis in motor imagery experiment

EDM is a process of machining electrically conductive materials by precisely controlled electrical discharge through a small clearance gap that occur between an electrode and a workpiece in the presence of a dielectric fluid. Through EDM process, the material of workpiece are melted and gap distance will increase. In order to maintain a stable spark, the gap must be controlled. This paper presents control spark gap system of EDM using PID controller with voltage and position feedbacks. The results show Time Rise (Tr) of PID control with voltage feedback has a value about 75 seconds and Time Rise (Tr) of PID control with voltage and position feedbacks has a value about 18.6 seconds. The average error of gap distance in PID control with voltage feedback is 55.56 and the average error of gap distance in PID control with voltage and position feedbacks is 48.53. Addition of the position feedback is used to increase the rise time and stabilize distance the electrode and the workpiece.

Spark Gap System of Electrical Discharge Machining (EDM)

Electrical Discharge Machining, EDM is one of the technologies used for surface texturing such as the embedded micro-dimples on the metallic acetabular cup. During the machining process, changes in the gap distance may lead to load changes from open to short circuit. Limiting the load current under short circuit conditions and load voltage under open circuit conditions is the requirement in this system. Power supply is one of the elements that controls the process parameters which is related to improve the machining condition as well as Material Removal Rate (MRR). A considerable number of power supply design method were proposed for various EDM application. This research proposed a Switch Mode Power Supply method implementing new design of Flyback power supply which can stabilize the voltage during open circuit condition as well as during discharge condition. Experimental studies were conducted to verify the capability of Flyback power supply by machining eight micro-dimples in lower position and twelve micro-dimples in upper position, both in circular arrangement on metallic acetabular cup. Research conducted shows that the Flyback power supply improve the consistency of MRR when compared to Linear power supply. This may help to predict the machining time, thus improving the production of microdimples in required time.

Azli Yahya

Papers

Design of biped hip simulator using SolidWorks

An investigation of hard-on-soft contact: for reducing friction in hemispherical cup

Brain-computer interface algorithm based on wavelet-phase stability analysis in motor imagery experiment

Spark Gap System of Electrical Discharge Machining (EDM)

Consistent machining of electrical discharge machining power supply towards hip implant surface texturing