HV power distribution system circuit breaker are important devices in substations. Such as Malfunction or deterioration of equipment with in the substation will directing impact on the stability of the power distribution system and affect the reliability of the system. In addition this means that it is necessary to assess the actual condition of the proper condition-based operation and maintenance. Thus this thesis presents condition assessment procedure for equipment by using technical information visual inspection by Weighted Scoring Method. Weighting technique is used to determine important weight testing methods of devices by using Analytic Hierarchy Process (AHP). Testing methods for circuit breaker are such as visual inspection contact timing test. Scoring technique is divided into 1-3 levels by classifying on actual evaluate equipment consisting of consisting of good moderate bad. This thesis proposes a software development in order to organize the database and calculate the analysis of the condition of equipment in 5 HV substations. The evaluation results will be divided into 3 levels good medium and bad condition. According to the evaluation level the maintenance types are separated into 1) regular maintenance 2) increase the frequency of maintenance and monitoring of the test 3) equipment must be improved urgently. Finally abnormal incidents of equipment and cost of HV equipment maintenance can be reduced in effective way.

Non-destructive test with Acoustic Emission technique was used for monitoring of the corrosion in the above ground oil storage tank. In the analytical characteristics of acoustic emission wave however Acoustic Emission test has to be prior used for the location detection of corrosion especially indication of the severity of corrosion. In this research the relationship between the corrosion rate and the sound wave energy was studied. The corrosion and damage detected on the surface of the aboveground storage tank was determined by the Acoustic Emission Test. Nine pieces of low carbon steel grade SS400 was soaked in sodium chloride solution in simulated tanks at concentrations of 1.5 3.5 and 5.5 wt%. Next the corrosion activity was checked by performing with the Acoustic Emission Testing for 1 hour and thus calculating the corrosion rate of the test specimens. From the experiment it was found that the rate of corrosion affects the Acoustic Emission Energy. The corrosion rate was increased with the concentrations of the solution increasing from the corrosion process. The corrosion rate was also increased with the sound wave power increases. Therefore in order to achieve the corrosion rate and the position of the defects on the inner surface of the tank non-destructive testing with acoustic emission technique can be factually chosen for this specific application.

Brake system is used the friction between disk and pads. In the driving conditions the brake behavior from the driver is difference. Based on this reason the damage on disk and pads are occurring. Nowadays the ratio of compound materials in pads is several and involved automotive industry has not available enough to experiment. Thus it is difficult to brake pads damaged analyzing in several driving conditions. In this problem the mechanical property tester is main tool for experimenting. And test procedure based on the Brake lining and disc brake pads compressibility JIS D 4413 [7]. The experiment emphasizes on the flexibility behavior and internal energy by volume with 3 types of brake lining and pads. For the experiment focused on conditions by normal apply brake repeat apply brake and suddenly apply brake. The results revealed the normal apply brake condition the maximum and minimum of flexibility behavior was appeared on brake lining and pads type A and type C with testing temperature at 2000C. By the repeat and suddenly apply brake conditions the brake lining and pads type C and type A with 300C is given to the maximum and minimum flexibility behavior. In case of internal energy by volume the maximum and minimum energy was appeared on pads type C and B at the 300C of testing temperature. For the testing temperature at 200 and 4000C the pads type A and type B were got the maximum and minimum energy respectively. On the other hand at the high flexibility behavior is given to high internal energy at the high temperature of the apply brake condition.

Nowadays an automotive industry steadily has been growing and playing a major role on economy development for many years. The crash box is one of the most important parts for safety but it was found that the crash boxes manufactured domestically are not met international standard requirements. This is due to process and material limitation. This process for automotive safety test requires high budget and there is unclear approach for specific test. Therefore a study of crash boxes referred to energy absorption project was conducted as the alternative materials for product. Consequently this project was aimed to design and test crash boxes which made from the diversity of the alternative materials such as aluminum aluminum reinforced by foam resin reinforced by fiberglass resin reinforced by water hyacinth and resin reinforced by water hyacinth and husk. In addition it was also emphasized in studying energy absorption behavior and physical deformation of crash boxes after dynamic and static energy being applied. The experimental works were applied for these tests in partly referenced to US NCAP and ECE R29 standard for automobile collision test. Testing all types of crash boxes indicated that the aluminum reinforced by foam type was able to absorb energy at 189 MJ/m3. It is higher than resin reinforced by water hyacinth and husk at 1 MJ/m3 as 188 times. Furthermore the comparison of the energy absorption (per unit volume) between the aluminum reinforced by foam type and the steel type from the previous project equivalent 20 MJ/m3 found that it is 8.45 times of difference. While the front impact test was not successful because the size of crash boxes was not suitable for the energy volume. It was a cause for non-available calculation of energy absorption value.

The aim of this research is to study the varieties of weight density distribution affect to the center of mass and vehicle stability. The weight density distribution tester was designed and changed the position of mass. Base on the center of mass is main points of vehicle stability. On the other hand FMCSA standard was applied to field test for considering of the brake performance and vehicle stability. The results of research discovered to the mass distribution on horizontal plane and fixed position Y1 are absolutely influence under an increasing 50 kilograms of mass condition. For the mass distribution on longitudinal plane and fixed position Z2 and Z3 are affected to the increasing of mass 100 and 150 kilograms respectively. Otherwise under an increasing of mass 200 and 250 kilograms there is non-influence to the weight density distribution. In term of the braking performance it’s depends on the lateral mass distribution especially the center position of mass installed on longitudinal and horizontal plane and close up on the front axle (Y2). For the vehicle stability results the position (Y2) is the highest influence for yaw rate and sideslip. Otherwise the position (Y3) or the position of mass installed on longitudinal plane and nearly at the left wheel on the rear axle. Additionally wheel lock-up condition was appeared on the front axle only. Because the behavior of the weight distribution on front axle was decreased lead to mass distribution on longitudinal plane.