جستجوی مقالات مرتبط با کلیدواژه « Pin » در نشریات گروه « برق »

In this article, the author proposes a sensorless direct torque control (DTC) of permanent magnet synchronous motor (PMSM) fed by four-level neutral point diode clamped (NPC) inverter using a neural networks (NNs) technique. neural PI (PIN) regulator is used for controlling the rotor speed of PMSM and NN controller applied in switching select stator voltage. The technique proposed in this article can minimize the stator flux ripple, electromagnetic torque ripple and harmonic distortion of stator current, and especially improve system good dynamic performance and robustness in high and low speeds.

The effects of zinc dialkyl dithiophosphate (ZDDP) concentration on tribological behavior of refined, bleached and deodorized (RBD) palm kernel were analyzed using a pin-on-disk tribotester. RBD palm kernel was selected as base lubricant due to its availability, low price, renewability and environmental friendly. Commercial mineral oil (SAE 40) was used for comparison. The tests were performed at 2.5 m/s of sliding speed under 9.8 N applied load for 60 minutes and temperature at 25 ( 2 ). Worn surface of the pin was measured by optical microscope to understand the wear mechanism involved. Experimental results showed that the addition of 5wt% of ZDDP has reduced the coefficient of friction to 21% compared with SAE 40. However, the anti-wear property was still lesser, approximately at 23%. Besides, the tribological behavior of RBD palm kernel was improved with ZDDP additive concentration above 1wt% where the best performance was at 5wt%. At this concentration level, ZDDP additive was able to protect the surface against wear and oxidation, and at the same time reduces coefficient of friction, wear rate and surface roughness values.

Significant improvements in bio-technology and bio-engineering have composed wonderful opportunities to understand and manipulate the bio-structures. Biochips are known as electronic platform for automating the bio-chemical operations in order to decrease time, cost and increase flexibility of operations. Digital micro/nano fluidic biochips are two dimensional arrays of controllable electrodes that can convey droplets around the chip to perform the assays. Each electrode is controlled via an external pins and decreasing the number of pins is very critical in feasibility of biochip construction. In this paper, a new FPGA-inspired architecture is proposed for micro-fluidic biochips in order to create the ability for configurability to improve the flexibility of biochip and reduce the number of controlling pins. Our simulations show that in the new architecture, number of required pins is improved 6.35x rather to than direct addressing method Griffith (2005) and total experiment time is reduced by 34% with higher level of configurability, flexibility.

The tribological investigation in term of coefficient of friction and wear resistance of refined, bleached and deodorized palm olein was conducted using a pin-on-disk tribotester. Palm oil was selected as a candidate due to its superior tribological properties and its large production, that can lead to the mass production of bio-lubricant. The material of the pin and the disk is Titanium (Ti6Al4V).The experiments were conducted following the ASTM G99. The normal load was 9.8N and the observation time was 1 hour. The sliding speeds were 0.25m/s and 1m/s. In this research, only 5ml of the test lubricant was applied at the beginning of the experiment to investigate the capability of the lubricant to maintain its function. To make sure the lubricant do not subside due to the centrifugal force from the rotating disk, a groove was crafted on the disk. In this research, coefficient of friction and wear rate were calculated. From the analyses, the coefficient of friction calculated for palm olein was the lowest for both sliding speed conditions, while the wear rate obtained showed that palm olein was an efficient lubricating oil at a low speed and had high wear rate obtained at the high speed.