There is one fact that lead composite material to be a unique material among others. Its properties could be settable or flexible with arrangement of composition, orientation and production procedure. Meanwhile other materials seemed to have fixed set after fabrication. Nowadays, one of the widely developed structural composite is polymer based composite with inorganic reinforcement. It is useful in automotive or aircraft component because reasonable strength and much lower density compare to metal. In this study, e-glass fibers were manually laminated with polyester resin in open die using brush. This method is widely known as hand lay up. Fibers were set in stacking sequences of 0 o , 90 o , and 0 o , means a fiber is in perpendicular direction to its neighbor fibers. After complete dried up, composite panel is cut of accordingly to ASTM standard for tensile and compressive testing specimen. In order to examine hole effect, center of gage length specimen was drilled off. Namely, specimen will be distinguished as no hole specimen and open hole specimen. Results showed tensile strength of 200.58 MPa and 155.22 MPa, compressive strength of 335.73 MPa and 254.1 MPa, for no hole and open hole specimen respectively. Introducing open hole reduces mechanical strength of composite both tensile and compressive. It could be mechanical consideration for safety design of material composite application. Failure mechanism of composite is also influenced by existence of open hole. When no hole specimen will experience failure at near to grip (LAT), open hole specimen has fracture line propagate from hole into width (LGM).
The present paper is concerned with experimental study of thermal performance of a Photovoltaic/Thermal (PV/T) tray dryer. The PV/T tray dryer considered consistes of a solar cell module of 100 W P integrated with a cabinet dryer. The cabinet dryer is covered with tranparent UV plastics allowing direct heating from solar radiation The ccoling air of the solar cell is used as drying medium and circulated by solar cell powered DC fans. The experiment was performed under no load condition at different weather conditions, i.e on a cloudy day and a clear day. During the experiment, the daily average solar radiation and ambient temperature are respctively 324,7 W/m 2 and 26,5 o C (cloudy day) and 727 W/m 2 and 27,9 o C (clear day). The maximum air temperatures attained in the dryer chamber are 34,4 o C (cloudy day) and 40,5 o C (clear day). There is air temperature variation among the trays, however the variation is insignificant, only at the order of 1-3 o C.
Power House Division (PHD) is one of the divisions that is part of PT. ABC. As an electrical energy supplier in XYZ area, Power House Division consist of four Power House, which each Power House has several engine. The first Power House (PH 1) consist of two Diesel engine Generator (DG) and one Gas Turbine in the second Power House. The third and fourth Power House consist of seven Diesel engine Generator. To keep the engine performance stable that is produce maximum power and prevent unknown damage that it make engine trip then the overhaul activity done. overhaul activity is carried out the process of replacement and recondition of spare parts of all parts of the engine. The recondition process is done in the cylinder head. Cylinder Head is an important component of a machine function as a combustion place and as an inlet and airway. There are long stages done In the process of recondition cylinder head from the demolition of cylinder head components to the re-installation of these components. There is a cylinder head that has crack, so it can not be recondition. It should be replaced with a new cylinder head. The machining process is used recondition cylinder head. They are Cutting, Lapping, and Grinding. In the pocket cylinder head, the recondition is found that it has a rust so that the size of the pocket and oversize that it has sticks around the pocket. Grinding process performed on uneven parts of valve.
A main drive is an important mobilizing motor component in a raw mill. Due to the extremely condition of constant operation of the raw mill results in failure of the main drive. This disturbs the raw mix intake and halts the next processes. In order to observe and diagnose the cause of failure on the main drive, it is important to conduct a maintenance. The Predictive maintenance technique utilized in this research is the vibration analysis technique. The measuring process of the vibration is conducted through the use of transducer velocity in radial and axial directions on the drive and non-drive components of the RIM03 motor and the symetro gear. The vibration, spectrum, velocity, and speed of rotation are analyzed in the x-Viber. Based on the vibration measurement data, the root cause of vibration can be analyzed through spectrum velocity. In this research, the critical result is found at the LS symetro gear. The occurred problem on the LS symetro gear is caused by misalignment shaft on the symetro gear connecting to gear pinion. The solution which can be applied is heat treatment to the shaft, therefore misalignment can be reduced.
The air conditioning machine commonly used is air conditioning system with a vapor compression cycle. The use of air conditioning machines consumes more electrical energy than other household appliances. In this study, the addition of the water mist method in evaporative cooling system with variations of distance of 20 cm, 40 cm, 60 cm so that the energy consumption of split type AC (Air Conditioning) of machines is more efficient. The results showed that the pressure of the condenser using water mist was lower 48 Psig than the pressure of condenser with a cooling load of 2000 W, and lower by 34 Psig of the pressure of condenser without the cooling load. Meanwhile the temperature of the air entering the condenser (Tout) after using a water mist has lower temperature than without the water mist, therefore it can save electricity consumption in the compressor. The temperature of the lowest inlet air of the condenser reached at the use of water mist with a distance variation of 60 cm was 28 ℃. And the relative humidity (RH) relatively decrease at the exit of the condenser using water mist with distance variation of 60 cm length was 59.6%. The compressor power decreased lower using a 60 cm distance water mist of 0.52 kW compared to without using a water mist with a 2000 W load of 0.56 kW. So that COP using water mist higher about 5.24 than without a water mist of 4.72. The highest COP was obtained using water mist at a distance of 60 cm
