จำนวน Repository ( 3447 )
A Solid-State Device for Fault Protection in Low Voltage Wind Turbine System
This paper presents how to design and build electrical protection equipment to apply for a wind turbine generator system which is modeled on low voltage 3 phase 380 volts system. This electrical equipment acts as a switch to open-close an electrical circuit to prevent an electrical system as well as equipments or devices in the system. It will open the circuit quickly and decrease the contact arcing of a circuit breaker. The implementation of power electronic properties is used instead of mechanical parts which is called “Solid-State Beaker”. This article presents a method of solid-state breaker simulation on the mathematical analysis via MATLAB/ Simulink program in the cases of fault occurring in an electrical system. The simulation is used as a comparison when it is brought into the system. The fault voltage is detected by RMS Method which is implemented in LAB View program. The detection signal will be sent to the solid-state breaker and order it to cut off all three lines simultaneously to confirm the efficient running of solid- state breaker. But this paper has not yet considered the effect of Harmonic.
A Study of Coconut Oil Pressing Machine
The technology development has been continuing to solve the cost problem aiming to reduce work time to streamline the existing machines to be more efficient and productive including designing the devices to replace human labor. In present paper the author has an idea to develop and transform the old press machine which has faced the issues of the deteriorated helix core bunt motor when overloaded less productivity to hydraulic cylinder. This paper examined the development of the coconut oil pressing machine from old model to hydraulic cylinder system. In operating principles the developed machine uses the motor pumping the hydraulic oil into hydraulic pump the oil fuel was restricted by hydraulic pump to increase the pressure transmitted to the solenoid valve which is responsible for changing the direction of the oil flow resulting that the cylinder moves up and down under the control system. The cylinder presses the coconut pulp The study of the development of coconut oil press machine was initiated by drying the 3 kg coconut pulp in the sun to obtain the 0.2038 kg (or 160 ml) coconut oil. In this study the hydraulic cylinder presses 3 kg dried coconut pulp into 1.1858 kg (or 946 ml) coconut oil or accounted for 83.08% as compared the old machine. The payback period is within 29 days.
Green Management Improves Organizational Productivity:Cases of Total Quality Management and Lean Initiatives
The organizational environments have been dynamically changed. Chief executive officer must turn an ailing organization around by rethinking a new mission. With global competition and trend of environmental performance improvement the green management then becomes substantially strategic orientation. The new management techniques such as Total Quality Management and Lean Management are introduced to the organization for achieving its new mission. The researchers use case studies method to describe the causal relationship between productivity derived from continuous improvement initiatives and green management by presenting four empirical cases. The results of all cases were measured by differentiation and integration criterion and then quantified by the concept of Time-Driven Activity-Based Costing. The findings of this paper are the causal inference and continuous improvement initiative procedure
Marketing Factors, Sociological Effects, and Attitudes upon Sufficiency Economy’s Book Purchase of People in Bangkok Metropolitan
The research of the factors influencing people’s purchase of the book about sufficiency economy in Bangkok was aimed at studying 1) attitudes towards sufficiency economy 2) marketing factors and book purchasing behavior about sufficiency economy 3) sociological effects upon sufficient economy and 4) factors influencing people’s purchase of the book about sufficiency economy in Bangkok. The questionnaires were constructed as a tool for collecting data from 400 samples of the people in Bangkok who used to purchase the book about sufficiency economy. The results of hypotheses tests at the statistical significance of 0.05 showed that 1) awareness knowledge liking and preference in attitudes towards sufficiency economy had no influence upon a purchase of the book about sufficient economy 2) marketing factors including product price promotion and place had influence upon purchase of the book about sufficiency economy 3) sufficiency economy book purchasing behavior the number of the books about sufficiency economy had influence upon book purchasing behavior 4) morality and sufficiency aspect in sociological effects had influence on sufficiency economy book purchasing behaviors.
Optimization of the Aluminum Riveting Process Using an Experimental Design Technique
The purpose of this research is to determine the optimal factors existing in the aluminum riveting process. First a 25 full-factorial design was used to screen five factors and two levels by selecting a lapping-joint method using only one rivet which exhibited significant riveting shear. The five riveting parameters used were press force 5000 and 8000 newtons a thickness of material of 2.5 and 4mm a size of hole of 4.7 and 5.2 mm over long rivets of 4.7 and 5.2 mm and press times of 5 and 15 seconds. There were three parameter levels: thickness of the metal (2.5 3.2 and 4.0 mm) size of the hole (2.5 3.2 and 4.0 mm) and size of the over-long rivet (4.5 5.6 and 6.7mm) then a Box-Behnken design was used in order to analyze the data and find the optimization point. The experiment found that a standard rivet has a shear strength resistance of 1113.30 newtons. The study methodology was to prepare the riveting specimens use by selecting a lapping joint per one rivet to test the mechanical quality and shear. The results of the experiment show that the optimal conditions (to a statistically significant degree) were to use a 5.2 mm hole a 2.8 mm level of thickness and a 6.3 mm over-long rivet. The optimal point for the shear test was 1417.55 newtons and an over-shear strength of 303 newtons could be increased by 27.32 percent.