จำนวน Repository ( 1174 )
การศึกษาพฤติกรรมค่าการนำความร้อนแบบไม่เชิงเส้นของวัสดุความเสียดทาน
Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the conductivity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 200 to 400°C and cooled down from 400 to 200°C at 1 5 and 8 MPa of pressure respectively. By standard JIS D4413 testing condition of pressure was referred. The non-linear of conductivity value are calculated from the temperature under steady state condition. As a result of testing there are several of parameters effecting on the non-linear conductivity value. The brake pad that is a mix of high-fiber affects the fluctuation of thermal conductivity. At the same time lubricant in the brake pad cause the stability of conductivity value in different temperature range at the same pressure. On the other hand the brake pad mixed hi-copper inspires the narrow range of conductivity value in different pressures at the same temperature. Moreover the conductivity value as a mention is inversely proportion with the coefficient of kinetic friction.
การปรับปรุงสมบัติทางกลและความสามารถในการขึ้นรูปของพลาสติกชีวภาพที่ทำมาจากโปรตีนกลูเตนโดยการใช้ยางธรรมชาติ
The aims of this research work were to enhance the impact resistance and processibilty of wheat gluten (WG) by the addition of epoxidized natural rubber (ENR) compared to glycerol. This work was divided into two parts: to study the optimum ENR content for improvement of WG and the effect of together functions between ENR and glycerol on the properties of WG. Tested specimens were mixed and prepared by internal mixer and compression molding machine respectively. ENR and glycerol were varied from 10 to 40 phr. The effects of modifier types and contents on WG were evaluated by tensile impact and water absorption testing and thermal analysis. Fracture behavior and rubber dispersion were investigate with scanning electron microscope (SEM). The result revealed that the increase of ENR or Glycerol contents led to the decreases in tensile modulus and strength except for modifier content of 10 phr whereas elongation at break and impact strength increased. Glass transition temperature (Tg) of modified WG tended to decreased with the increase of ENR or glycerol contents especially for glycerol. The presence of glycerol affected on the decomposition temperature (Td) values but those were unchanged for case of ENR. Water resistant of WG specimen was improved by the presence of ENR whereas the increase of glycerol led to weight loss at immersion time of 2880 min. For the effect of ENR : glycerol ratios it indicated that glycerol enhanced tensile resistances but suppressed impact and water resistances of modified WG by ENR. Sizes and dispersion of ENR particles were improved by the addition of glycerol. Tg and Td values of modified WG by ENR and glycerol increased when ENR fractions were increased.
การศึกษาพฤติกรรมการถ่ายโอนความร้อน และการสั่นสะเทือนของจานเบรกแบบตรง/แบบกลับที่ส่งผลกระทบต่อความสามารถการเบรก
The purposes of this study were to investigate the heat transfer and the vibration characteristics caused by front and back vented brake disc which had physically different shapes affecting braking distance. In accordance with the theory of heat transfer the heat transfer rates of two types of brake disc were different and played an important role in the deformation during usage. The single dynamometer was conducted to the experimental work as an engineering tool with boundary conditions according to JASO C406 standard. One degree of freedom (DOF) acceleration signals on the brake caliper were analyzed. The results obviously discovered that the back vented brake disc was able to reduce the vibration up to 43.5% comparing to the front vented brake disc in case of the braking temperature 200C initial breaking speed 50 km/h and the hydraulic pressure of 4 MPa. Besides the hydraulic pressure at 4 MPa generated the maximum vibration. Furthermore the initial braking speed and the braking temperature were also the important factors. Regarding braking distance results the results of the experimental work obviously discovered that the back vented brake disc created braking distance shorter than front vented brake disc. Besides there were important factors as braking temperature hydraulic pressure and initial speed of braking. Especially the high braking temperature caused an increase of deceleration and a decrease of braking distance. Moreover the high hydraulic pressure produced a deduction of braking distance and an increase of deceleration. Finally the initial speed of braking directly varied to the braking distance
เครื่องผลิตตะเกียบไม้ไผ่ด้วยระบบควบคุมอัตโนมัติ
This research presents a bamboo chopsticks machine with automatic control system. The production of bamboo chopsticks the current will be cut to get the machine to enter the bamboo chopsticks using the machine. The machine will hammer bamboo rotation of the electric motor. The AC motors with high power. Currently the production of chopsticks mostly small businesses. Lower costs which resulted in lack of effective security. This research presents the design and techniques with bamboo chopsticks production automation. The objective is to make the production of bamboo chopsticks are secure and compliant. To increase productivity and reduce the danger of the machine. In designing the Arduino technology is used in the development of electronic prototypes designed to be user for both hardware and software advanced application control equipment used in the production of chopsticks for safe to use on the incidence of danger from the use.
การวิเคราะห์ผลกระทบของฮาร์มอนิกเพื่อแก้ปัญหาเศรษฐศาสตร์ในระบบไฟฟ้ากำลัง
This research proposes technical performance evaluation and economic decence for the combination of harmonic correction devices in Industry. Currently an electronic device is popularly applied in power network. Although it is a higher performance device than the existing device it still causes the power quality issues and then network failure. Especially harmonic disturbance in the network it is a harmonic source that generates harmonic current into the network. Many types and solutions are available in the present time therefore the suitable and optimal financial solution must be considered. A network model for the analysis of harmonic correction devices suitable solutions and optimal financial has been established in the simulation software that bases on the power and Break Even Point (BEP) equations. The results of analysis shown that the performance of harmonic correction devices suitable solution and BEP of investment in match to the using of a detuned filter bank and an active harmonic filter (case 8) thus these information will be valued for the end-user.