Applied Mechanics and Materials Vols. 110-116

Abstract: Scaling down the integrated circuits has resulted in the arousal of number of problems like interaction between interconnect, crosstalk, time delay etc. These problems can be overcome by new designs and by use of corresponding novel materials, which may be a solution to these problems. In the present paper we try to put forward very recent development in the use of novel materials as interlayer dielectrics (ILDs) having low dielectric constant (k) for CMOS interconnects. The materials presented here are porous and hybrid organo-inorganic new generation interlayer dielectric materials possessing low dielectric constant and better processing properties.

Abstract: It is not possible to eliminate all the mistakes people make. People are not mistake proofed by their nature. But organization can avoid these mistakes from reaching the customer, which is known as a defect in this case. Mistakes can be stopped as soon as they happen at least. Poka Yoke is very simple concept in nature. The basic concept of this is avoiding the problems by correcting the process. Poka-yoke is a quality assurance technique developed by Japanese manufacturing engineer Shigeo Shingo. The aim of poka-yoke is to eliminate defects in a product by preventing or correcting mistakes as early as possible. Poka-yoke has been used most frequently in manufacturing environments. Japanese industrial engineer Shigeo Shingo developed Poka Yoke [1](to avoid (yokeru) [2] inadvertent errors (poka) ) along with "source inspection" as a means for achieving Zero Quality Control (ZQC). Shingo introduced these ideas in his book Zero Quality Control: Source Inspection and the Poka-yoke System. Poka - Yoke systems reduce the cost of failure dramatically. No defective part will be passed to the next process. So at the end of the process you can trust that you have a good quality parts on your hand. Poka yoke is one of the critical steps in the lean journey. This project implements Poka-Yoke system for Gear assembly. Project system can recognize that the worker has to pick gear as per defined sequence. Even it can recognize the position of the gear when all process is done successfully then signal send to Press to inject gear assembly in engine.

Abstract: This project aims to design and develop a working prototype of a walking assist device. Spring and brushed DC motors are adopted to assist human being standing or walking by lessening the amount of force subjected to the knee. Two DC motors are controlled by the high current capable motor driver which is specifically designed for heat management. Moreover, an 8051 microcontroller provides interface between the sensor ADC input, keypad manual input, intelligent controller and the DC motors.

Abstract: This research article presents the architecture analysis and design of Attitude determination and control subsystem (ADCS) of the Pico-Satellites especially the CubeSat, developed and launched into the Low Earth orbit (LEO). ADCS is not a stringent requirement for all the CubeSat missions but several missions were specifically designed to test and validate the ADCS. This paper contributes in evaluating the previous ADCS of CubeSat and presents an optimal ADCS design and a recipe for any CubeSat mission and specifically for the upcoming ICUBE of the Institute of Space Technology (IST), Pakistan. The proposed ADCS for ICUBE includes GPS receiver as position sensor while magnetometer as attitude sensor and magnetic coils as the active actuators. The determination will be done by Kalman filter and LQR will be used as a controller.

Abstract: Three dimensional molecular dynamics simulation on the nanocutting of monocrystalline silicon is carried out to investigate the material deformation behaviors and atomic motion characteristics of the machined workpiece. A deformation criterion is developed to determine the material deformation and phase transformation behavior in the subsurface layer based on the single-atom potential energy variations. The results show that the machined chips suffer a complex phase transformation and eventually present an amorphous structure caused by the plastic deformation behavior. A polycrystalline structure is obtained on the machined surface. Both plastic and elastic deformation simultaneously takes place on the machined surface, and elastic deformation takes place under the machined surface. In order to further unveil the mechanism of nanocutting process, the displacements of all atoms are also simulated. The simulation results shows that different atomic motions occur in different regions in the workpiece, and the chips formations occur via extrusion.

Abstract: — An extended predictive filter is presented for attitude determination of Micro-satellite based on the basic theory of predictive filter. This algorithm enhances the precision of kinematics equation, accurately estimates satellite attitude angle and angular velocity using measurement vectors from magnetometer and sun sensors by predicting model errors and angular velocity errors one step ahead. In addition, a new measurement model is derived about angular velocity, which improved the efficiency of the use of measurement vectors. Simulation results show both the high reliability and precision of this method.

Abstract: This paper present about solar energy electric with the capacity 4400voltampere, 3x220volts, 50hertzs. This capacity is assumed enough for many household, home industry, polyclinic, offices. In this case that solar panel is used “sliver cells” type because, use less silicon, more efficient, flexible, transparent, bifacial, thin. This system is build with charge controller utility to battery bank and from battery bank to 3-phase inverter. The 3-phase inverter is useful to convert direct current to 3-phase alternating current voltage. 3phase inverter used is consist of six unit of IGBT components. The output of 3-phase inverter is connected to input 3-phase stabilizer, and the output of 3-phase stabilizer is to lead to the loads. The output voltage of 3-phase stabilizer is detected and to be input to PLC (Programmable Logic Controller) Festo FC-34, because PLC to control change over-switch that the function as actuator with 5 seconds setting time, is the load supplied by solar energy electric, electric from PGL (Public Grid Line) or the electric from generator set. The alternative is ordered according with sequence of operation cost. The result of research, the output voltage from stabilizer 218.5volts, the input voltage of charge controller 56.16volts, the input voltage of inverter 48.0volts, the output voltage of inverter 205.6volts, electric current to the load 9.5amperes. If the output voltage of stabilizer less than or equal 190volts, so the PLC will actuate change over switch as the actuator to active to PGL power or to generator set power. It is found that overall system works effectively.

Abstract: On the basis of theoretical and experimental researches the new structures and formal methods of compositional micro program control units design are proposed. It is shown that optimization of hardware in the unit of microinstructions’ addressing can be achieved by application of the methods of multilevel implementation of automata with “hardware” logic, that need adaptation to the peculiarities of compositional micro program control units. It is proposed to use the methods of the logic conditions’ encoding, the codes of the states, the codes of the operational linear chains and their classes, and also the addresses of microinstructions. The new structures and methods of design were developed for all known structures of compositional micro program control units. The proposed methods permit to decrease the amount of programmable logic devices in the automaton of addressing’s circuit from 12% to 42% in comparison with known methods of design. The analytical estimations of hardware amount as the function of characteristics of initial flow-chart have been made up. These methods permit to expand the class of synthesizable control units. The conducted researches permit to find an area of the effective application of proposed methods of design. The purpose of work is minimization of number of the large-scale integrated circuit in circuit of automatons of addressing of CMCU due to application of methods of a structural reduction. The analysis of methods of realization of algorithms of control, element basis, methods of a structural reduction, methods of synthesis and optimization of compositional micro program control units are executed, the primary goals of researches are formulated.. (Abstract)

Abstract: The polycrystalline sample of (BiLi) 1/2 (FeV) 1/2O3 was prepared by a high-temperature solid-state reaction technique. A preliminary X-ray structural analysis exhibited the formation of single-phase compound with an orthorhombic structure. Detailed studies of electrical properties of the compound, investigated in a wide frequency range (1kHz-1MHz) at different temperatures by complex impedance spectroscopy (CIS) technique, showed that these properties of the material are strongly dependent on frequency and temperature. Ac conductivity is found to obey the Johnscher’s law. The M-H curve shows the presence of ferromagnetism in the studied compound.

Abstract: As the size of MOS device scaled down to sub 100nm, the direct tunneling current of gate oxide increases more and more. Using silicon nitride as gate dielectric can solve this problem effectively in some time due to the dielectric constant of silicon nitride is larger than silica’s.This paper derived the dielectric constant of silicon nitride stack gate dielectric,and simulated the direct tunneling current of strained MOS device with silica and silicon nitride gate dielectric through device simulation software ISE TCAD10.0,studied the direct tunneling current of strained MOS device with silicon nitride stack gate dielectric change with the variation of some parameters and the application limit of silicon nitride material.