Abstract This article reviews literatures concerning preparation of stable free radical DPPH (22-diphenyl-1-picrylhydrazyl) and its derivatives. The key intermediate playing an important role is diarylhydrazine. The article reports solution methods for problems in each step of the reaction. In addition it also shows the development of DPPH synthesis and other stable free radical DPPH derivatives besides DPPH

This study examined Factors Affecting Price’s Fluctuation of the SET50 Index Futures in Thailand Derivative Market during the Year 2011 – 2015. The objective was to study all of the factors which was affecting SET50 Index Futures’s fluctuation. According to daily closing price data of SET50 Index Future used for computing continuous return the period before the maturity and the volume of SET50 Index Futures were calculated the fluctuation by using GARCH (11). The results show that the data and fluctuation in the past affected the data and fluctuation in the present by the same direction considerated by the coefficient in ARCH and GARCH term of GARCH Model (11). The period before the maturity affected the return rate by the opposite direction which means the return rates had much more fluctuation when the period of time closed to the contract maturity. It showed that the coefficient of the period before the maturity was quite less than the one of ARCH and GARCH. Therefore the fluctuation of return rate in the present was possibly depended on data and the period of fluctuation in the past more than the period before the maturity. The remainder of the study can give information to the investors that they should be concerned not only about data and fluctuation in the past but the period before the maturity of SET50 index futures which may affect the forecast of SET50 index futures price for Hedge management. Thailand Future Exchange should be considered to adjust proper risk margin inaccordance with fluctuation rate in a period of time.

This paper presents compare results performance between two conventional controllers for bicycle robot. The bicycle speed control system was a highly nonlinear model multivariable and absolutely unstable. It has used for testing various design control techniques for low power. The objectives of this paper had to developed speed control which derived the mechanic model and experiment. Controllers are Proportional-Integral-Derivatives (PID) and on-off dynamic control. The dynamic system which also includes not stable friction effects the linear zed system model is used as a basis for the design to apply to speed. Computer simulation and experiment have been done controller are capable to control output speed wheel control system successfully. The results show PID controller better then on-off dynamic controller.