The joint for two different materials (AA5052 and AA6061) can be done by the Dissimilar Friction Stir Welding (DFSW) process. Therefore, this study was conducted to analyze the mechanical properties of dissimilar welding joints. In this study the DFSW process uses a tool with a shoulder Ø 17.8 mm and a cylindrical pin Ø 5 mm. FSW blocking is done on conventional milling machines with 1300 rpm, 1950 rpm and 2850 rpm tool rotation variations, while the welding speed variations are 43 mm / min, 130 mm / min and 240 mm / min. The results of mechanical properties testing showed the highest hardness value obtained was 55.3 HBN at 1300 rpm with 240 mm / min feeding, the highest tensile strength occurred for 1300 rpm and 240 mm / min feeding at 123.51 MPa. The fracture of the tensile test results generally occurs in the HAZ area and the AA5052 base metal Nugget. Investigation results show that the DFSW connection of aluminum alloy material AA 6061 and AA 5052 adapt is well connected, but in terms of general strength the tensile strength of the joint (HAZ and Nugget) is smaller than the tensile strength of the base metal. This DFSW connection adaptation is applied to connections that do not accept load or tensile strength due to the load received by the connection not to exceed the maximum tensile strength of base metal AA 5052

Computer programming is the implementation of a logical and coherent way of thinking even in simple problems. Computer programming training with visual basic is one way to take advantage of existing facilities in Microsoft Excel with a more attractive appearance so that it improves the way students learn. The training was carried out with participants of class X Automotive Light Vehicle Engineering Skills at Pangudi Luhur Muntilan Vocational School. The results of this training, students feel that this training is very useful, interesting, suitable, increases motivation to learn and adds insight or provisions after graduation.

The current problem of solar energy water distillation is in its low efficiency. Low efficiency is caused by inefficient water evaporation processes. Increasing the efficiency of water evaporation is done by controlling the rate of water entering into the absorber. The commonly used mechanical control system still has weaknesses such as the instability of the water entering the absorber. This causes less effective evaporation of water so that the resulting distillation efficiency is not optimal. The water rate input system for distillation in this study is based on a simple microcontroller. The microcontroller-based input water rate control system allows the rate of input water with a small but continuous flow rate so that the water evaporation process can be more effective. This study aims to improve the efficiency of solar energy water distillation by increasing the efficiency of the water evaporation process through controlling the flow rate of water inlet. The research was carried out by the experimental method. The parameters varied were: the rate of input water which was 0.3 ,

We promote a finite volume method to solve a water hammer problem numerically. This problem is of the type of fast transient pipe flow. The mathematical model governing the problem is a system of two simultaneous partial differential equations. As the system is hyperbolic, our choice of numerical method is appropriate. In particular, we consider water flows through a pipe from a pressurized water tank at one end to a valve at the other end. We want to know the pressure and velocity profile in the pipe when the valve closes as a function of time. We find that the finite volume method is very robust to solve the problem.

Increasing the temperature of inlet water is one way to increase solar distillation efficiency. Heat recovery using double glazing is a more straightforward way to raise the temperature of inlet water. In previous studies, the incoming water temperature was raised using additional equipment such as a solar water heater collector or utilizing the heat of wastewater from another water distillation system. The earlier studies' technique caused solar water distillation to be complicated, and the manufacturing cost was expensive. Heat recovery is a process of utilizing heat condensation of water vapor to increase the inlet water temperature. In conventional solar distillation, condensing heat is not used and wasted into the environment. Double glass is two glasses arranged in parallel, one on the top of the other. The distance between the glasses is 2 mm. The bottom glass is a 1 m 2 distillation cover glass. Water flows between the bottom glass and the top glass before entering the distillation model. The inlet water receives heat condensation so that the temperature rises. The increase in temperature causes heat loss to decrease and leads to efficiency improvement. This study aims to reveal the effect of heat recovery using double glazing to improve solar distillation efficiency. The study was conducted with laboratory experiments and simulations. The thickness of the bottom and top glass and the top glass area influence the heat recovery process. This study used two variations of glass thickness, namely 3 mm and 5 mm. The area of the top glass was varied by 0.1, 0.5, 0.7, and 1.0 m 2. The maximum efficiency improvement compared to distillation without heat recovery obtained is 39.6 % with a glass thickness of 3 mm and 51.0 % with a glass thickness of 5 mm achieved in the variation of the top glass area of 0.1 m 2