STUDI PERBANDINGAN KETAHANAN KOROSI STAINLESS STEEL TIPE SS 304 DAN SS 201 MENGGUNAKAN METODE U-BEND TEST SECARA SIKLIK DENGAN VARIASI SUHU DAN PH

There are many failures in a structure that is caused by the damage of the metal that support them. One of the problem which can cause the damage of the metal is corrosion. With its action, corrosion can make a metal  become thin, and in some cases can make a crack and fracture. Some factors are determine how fast the process is occured in corrosion process, for examples are the oxygen concentration, degree of acidity, and temperature. The purpose of this research is to know how is the role of that factors in corrrosion process. This research is implemented in three condision of temperatures (300 C, 500 C, 700 C), variation of HCl’s pH (0, 1, 2), and cycle environments condition. That will be combined and will be tested for about 7 days. After this execution, material will be measured for the decrease of the weight to give the value of corrosion rate. From this experiment, the rate of corrosion rises by increasing temperature and the decreasing pH condition. In all condition of this experiment, the SS 304 Stainless Steel has the better resistant to the corrosion in HCl environment.  The highest corrosion rate of cycle condition is 36.119,4 mpy for SS 201 Stainless Steel, and 515,5 mpy for SS 304 Stainless Steel. Form the micro photographs of corrosion happened on SS 201 Stainless Steel is pitting corrosion and SS 304 Stainless Steel is uniform corrosion. Keywords: Stainless Steel, Cycle and Corrosio

ANALISA PENGARUH KARAKTERISTIK KEKUATAN PERSAINGAN PORTER TERHADAP KINERJA SEKOLAH DENGAN PENDEKATAN BALANCED SCORECARD

The Schools have to anticipate the influence of external environments. The external environment analysis consist of the macro and micro analysis. The micro analysis used Porter`s five force model of competitiveness consist of threat of new entrans, the bargaining power of supplier, the bargaining power of customer, threat of substitutes schools  and rivalry among existing schools. The purpose of this study was to examine the Porter`s five force model of competitiveness on organizational performance of  school in balanced scorecard approach. Data for this study were collected from middle schools using a self-administered survey questionnaire. Hypothesis test showed that threat of new entrans, the bargaining power of supplier, the bargaining power of customer, threat of substitutes schools  and rivalry among existing schools examined had a significant impact on school performance in balanced scorecard approach.  but partially only threat of new entrans, the bargaining power of supplier, and rivalry among existing schools are significantly influence on schools performance in balanced scorecard approach. but for  the bargaining power of customers, and the threat of substitutes schools aren’t significantly influence on schools performance in balanced scorecard approach. Keywords: external environment,  micro environment analysis, Porter`s five force model of competitiveness, performance, balanced scorecar

PENGARUH DIAMETER PIPA SALURAN GAS BUANG TIPE STRAIGHT THROW MUFFLER TERHADAP UNJUK KERJA MOTOR BENSIN EMPAT LANGKAH

Exhaust muffler system is commonly called is one vital part of a motor vehicle. This serves as an exhaust silencer is removed from the machine until at a certain noise level permitted with little possibility of a decline in torque and engine power. This study aims to determine the influence of the exhaust pipe diameter of straight throw gasoline engine performance, pressure, exhaust gas flow rate and intensity of noise generated. From the results of research in getting that throw straight exhaust pipe diameter which was able to improve gasoline engine performance, pressure, flow rate of exhaust gas and noise intensity. This is evident from the results of research that shows that there was an increase by using a exhaust pipe diameters greater straight throw. Keywords: exhaust pipe, exhaust silencer and straight thro

PENGEMBANGAN DAN ANALISIS ERGONOMI KURSI OPERATOR MESIN VULKANISIR BAN DENGAN METODE REVERSE ENGINEERING

The likelihood of complaints occurring in the tire retreading machine operator is very possible especially if the seats are not as ergonomic. This situation occurs and will be redesign chair  process machine operators with a method of tire retreading Reverse Engineering (RE) with respect to ergonomic aspects. By analysis using finite element software simulations, we can determine the voltage that occurs in part the concept of tire retreading machine operator seat. So it can be seen clearly the force distribution that occurs in material unit concept tire retreading machine operator seat. To calculate the material strength analysis by finite element software can use the help of CATIA V5R14 software. This is intended to get maximum results and an accurate analysis. After the experiment, the voltage that occurs on a cushion of 1.81x106 N/m2 located on the bottom face of the middle cushion while the minimum working voltage is 1.81x105 N/m2 located on the bottom front cushion edges. The voltage that occurs on a cushion of 1.27x108 N/m2 located at the base of the curved pipe connections while the minimum working voltage is 1.27x107 N/m2 located at the base of a straight pipe connection. Ergonomics analysis obtained by using the method Rula when operators run the machine has the injury risk rate value is 2, which shows the attitude of the body is acceptabel and do not need to be changed for the long term. Keywords: ergonomic, chair operator and reverse engineerin

PENGARUH PEMASANGAN SIRIP PENGARAH PADA BUFFER TERHADAP UNJUK KERJA MOTOR BENSIN

Perfect combustion can improve engine performance and save fuel consumption. One of the requirements perfect combustion is a homogeneous mixture of fuel and air when entering the combustion chamber. Air and fuel mixture to become homogeneous in case of turbulence in the mixing. Buffer with director fin is used to provide additional mixing time between air and fuel at the same time create a turbulent flow before entering the combustion chamber. In this study the buffer fitted with director fins with different variations. The number of fins variation used in this study are 3, 4, 6, 8 and 10 with a variation of the angle are 45o and 60o. The analysis was conducted on the effective power and torque output and the FC (Fuel Consumption) needed from each variation condition buffer. From the results of testing on the condition of the buffer with 3 fins angled 60o obtain the highest effective power increase 5.92% and increase in the highest torque 2.66% when compared with the buffer without fins. The lowest FC (Fuel Consumption) in the buffer with 3 fin angle 60 ° when compared with the buffer without any fins at 4000 rpm with a 11.15% difference. Keywords: homogeneous, turbulent, buffer and fi

ANALISA TEGANGAN-REGANGAN PRODUK TONGKAT LANSIA DENGAN MENGGUNAKAN METODE ELEMEN HINGGA

In any design done must consider the strength of the staff. The strength that must be considered regarding the dimensions, materials, and stick structure. In the previous elderly rod product design, structural analysis found that by just using the help of software, so that the power structure of the stick product has not yet been fully elderly a top priority. This is because the previous data was found that the maximum load that can be received by elderly stick it is 45 N. It appears that the greatest stress occurs is still under the stress of the material itself permits. The voltage that occurs on the order of 6.47e +006 N/m2 located on the handle of the stick while the minimum stress acting on the order of 1.29e-008 N/m2 pipe located at the upper stalk. So the calculation needs to be done manually to review the results of previous calculations, in order to improve and enhance the strength of the product stick elderly. Finite element method is a numerical method used to solve technical problems and a symptom phisis metematis of which include stress, strain, strength, and vibration analysis. This finite element method to compare between the calculations using CATIA software and using the calculations manually. In this case the finite element method to be used is a 2D finite element method (field) is a triangular element with 3 nodes. Using Finite Element Method, the biggest stress on the element 5 with a large voltage of σx = 2.505 x 104, and the biggest strain on the element 3 with a large strain εx = 0.272. And failure obtained Theory states: Maximum Normal-Stress Theory declared safe. Because it is still within safe limits. Maximum Shear-Stress Theory  declared unsafe.   Keywords: stick, stress, strain and finite elemen