Design and fabrication of a simple cost effective spin coater for deposition of thin film

This paper describes the design and fabrication of an economical spin coater for depositing thin films.Spin coater is a machine that can dispense a liquid onto a substrate uniformly. Some desirable properties of Spin coater such as ability to make defect free and uniform thin film, accuracy in rotation control together with a closed optimized process chamber etc. are maintained in this prototype spin coater.The materials used for making thin filmliquefied in a volatile solvent. Here the system is fabricated by using a dc motor and simple electronics circuit, in which the spinning speed can be controlled very easily. In this design the spinning speed is up to 3,000 rpm that can be controlled step by step manually. ZnO thin films are successfully prepared through this spin coater by sol-gel process. This thin film isa mixture of Zinc acetate dihydrate, ethanol anddi-ethanolamine. Thin filmdeposition by this cost effective spin coater is a very simple technique and can beused widelyfor preparing films of uniform thickness

Temperature effect analysis on magneto-rheological damper’s performance

Magnetorheological (MR) damper is one of the most advanced applications of semi active damper in controlling vibration. Its use is increasing day by day in the vehicle suspension system due to its continuous controllability in both on and off state. MR damper’s damping force can be controlled by changing the viscosity of its internal magnetorheological fluids (MRF). Applying an external magnetic field viscosity of MRF can be controlled. Electromagnet such as solenoid coil is normally used as external magnetic field source. These coils are attached inside the damper’s piston head. When the damper operates these coils create heat. That’s why the conventional MR dampers normally face wide variations in temperature. This change of temperature results decay in MRF viscosity as well as post-yield damping of the damper. In this paper temperature effect on MR fluids viscosity and on MR dampers performance represented analytically and experimentally. Due to this temperature effect the deviation of MR dampers performance has shown here experimentally. Also a novel technique for solving the problem explained clearly

Development of an advanced semi-active damper using smart fluid

In this paper an advanced semi-active damper is designed and experimentally studied to investigate and establish its behavior. A prototype Magneto-rheological fluid Damper is designed as advanced semi-active damper due to its huge advantages. Magneto-rheological fluid with improved dispersion stability is prepared here as smart fluid. The relation between force and displacement for various current has been established to develop the semi-active damper model. In this study a fuzzy tuned PID controller is opted to achieve better response for a various frequency input. The proposed MR damper can be applied to vehicle syspension system and other suspension mitigation system widely. Moreover, the identified behaviour can help in further development of MR damper technology. The characteristics obtained from of MR damper is more realistic as it is obtained from experiments

Development of an simplified modeling control system for maximization of polymerization in a pilot plant

Polymer is obtained by a process called polymerization which is actually a chemical reaction to combine monomer molecules together. In this work a suitable model and control system was proposed for obtaining the maximum production yield of industrial grade polymer. Significant process parameters specifically system temperature (0C), reaction pressure (bar), and raw materials ratio (%) were selected as process controlling inputs. Differential pressure (DP) obtained from a series of experiments were fitted into a quadratic polynomial model by applying multiple regression analysis. By analyzing the response of three dimensional surface plot, contour plot and soling the regression model equation, the optimal process conditions are obtained. To optimize the interactions among the quadratic polynomial models Center Composite Design (CCD) technique under RSM was used. The results showed the best conditions or the optimized values for initial temperature, system pressure to initiate reaction and monomer gas ratio. Further the maximum predicted value of DP was also obtained at same conditions. At last the trail experiments are evaluated by using the optimum conditions to achieve the higher DP

Development and performance testing of a light weight portable solar rice cooker in rural areas of Bangladesh

Generally sunlight is one of the most potential sources of energy on earth. Among the total energy consumption, energy consumption for cooking is a leading component in developing countries. Most of the rural people in Bangladesh use biomass fuel for cooking such as wood, cow dung, jute sticks or other agricultural wastes. Hence, there is an attentive necessity for the improvement of alternative, suitable, cheap mode of cooking in Bangladesh. This paper presents the thermal performance of a light weight Portable Solar Cooker (PSC) using parabolic shaped umbrella with aluminum foil coating. An umbrella of 125 cm diameter was used as a frame of the portable cooker because it is more convenient to transport and its surface area is almost parabolic. The aluminum foil was attached to the inner side of the umbrella with white glue which acts as reflector plate. The focal length of the parabolic surface was 26.16 cm. The maximum temperature of the experimental water recorded was 98˚C at around 12 PM. The investigational time was from 10:00 AM to 01:00 PM. The cooking power and energy efficiencies of the PSC were in the range 37W to 149.3 W and 2.8 % to 11.59%, respectively

Optimal design of magneto-rheological damper comparing different configurations by finite element analysis

Magnetorheological (MR) damper is one of the most advanced applications of semi active damper in controlling vibration. Due to its continuous controllability in both on and off state its practice is increasing day by day in the vehicle suspension system. MR damper’s damping force can be controlled by changing the viscosity of its internal magnetorheological fluids (MRF). But still there are some problems with this damper such as MR fluid’s sedimentation, optimal design configuration considering all components of the damper. In this paper both 2-D Axisymmetric and 3-D model of MR Damper is built and finite element analysis is done for design optimization. Different configurations of MR damper piston, MR fluid gap, air gap and Dampers housing are simulated for comparing the Dampers performance variation. From the analytical results it is observed that among different configurations single coil MR damper with linear plastic air gap, top and bottom chamfered piston end and medium MR fluid gap shows better performance than other configurations by maintaining the same input current and piston velocity. Further an experimental analysis is performed by using RD-8041-1 MR Damper. These results are compared with the optimized MR Damper’s simulation results, which are clearly validating the simulated results

Experimental investigation on Magnetorheological Damper’s characterization

Magnetorheological (MR) damper is one of the most advanced application of semi active devices. Its use is increasing day by day due to its huge advantages and wide range of application. The force delivered by MR damper can be varied by changing the viscosity of its internal MR fluids. Till now no details experimental analysis has been accomplished by considering various parameters. In this paper a brief experimental analysis has been investigated with the help of Universal Testing Machine to characterize MR damper. To characterize accurately MR damper has been analyzed experimentally for different stroke length, stroke rate, stroke mode. From the experimental results it is seen that the force delivered by MR damper has a proportional relation with input excitation current, stroke length and stroke rate

Design and performance evaluation of a self-controlled magneto-rheological damper

Magneto-rheological (MR) dampers are semi-active control devices and use MR fluids. Magneto-rheological dampers have successful applications in mechatronics engineering, civil engineering and numerous areas of engineering. At present, traditional MR damper systems, require an isolated power supply and dynamic sensor, which requires large space. This paper presents the achievability and accuracy of a self-controlled, i.e., self-powered and self-sensing magneto-rheological damper using harvested energy from the vibration and shock environment in which it is deployed. Another important part of this paper is the increased yield stress of the Magneto-rheological Fluids. Magneto-rheological fluids that use replacement of glass beads for Magnetic Particles to surge yield stress is implemented here. Clearly this shows better result on yield stress, viscosity, and settling rate. The permanent magnet generator (PMG) is designed and attached to a MR damper. For evaluating the self-powered MR damper’s vibration mitigating capacity, an Engine Mount System using the MR damper is simulated with the help of ANSYS software. The ideal stiffness of the PMG for the Engine Mount System (EMS) is calculated by numerical study. The vibration mitigating performance of the EMS employing the self-powered & self-sensing MR damper is theoretically calculated and evaluated in the frequency domain

Modelling and performance analysis of electric rice cooker

In modern age, technology is being used for saving time, energy and power in all cases. Undoubtedly rice cooker is an example of all these. It is a combination of cocking and warming mode by which rice is cooked and kept warm. The purpose of this paper is to model an electric rice cooker with improved warming mode. Generally bacteria can grow upto55˚ temperature and the condensation of moisture occurs below 65 temperature which causes rice spoiling. So it can easily be prevented by keeping cooked rice above 65 temperature. By following this principle two warming coil of nicrom wire are added, where one is at upper parts and another is at side wall around the fiber paper. By this process a locally available rice cooker is designed which is capable of keeping rice fresh and warm for 5-7 days and saves energy from12 to 15 units per month

A Battery Charge Balancing system with reducing inrush high spike current for electric vehicle

A charge equalizer system is suggested for use in the future battery-packs employed in plug-in vehicles or house used in UPS-based supply systems deriving energy for supplementing the grid-connected main supply. Such applications are becoming common in Distributed Generation on spot from sources of solar (or wind), especially when grid connected power-supply is interrupted for some reason. The charge equalizer circuit is using resonant circuit, being operated by the switching frequency showing results the effect of when compared to the resonant frequency. The inrush current raises in the switching components of the resonant circuit due to inductor components. This inrush current may damage the switching component and increase the total system cost. In this work, flyback snubber circuit consisting of diode and capacitor has been used for reducing inrush high spike current. In addition, Zero current switching is achieved in this system for reducing the circuit losses