Maulana Rachman’s scientific contributions

Abstrak Peralatan pemadam kebakaran permanen dan pemadam kebakaran ringan (APAR), adalah perangkat untuk memadamkan api akibat kebakaran. Apar sesudah dan sebelum di gunakan. Pengujian ini sangatlah penting di lakukan untuk mengetahui kesiapan apar harus dapat di gunakan setiap saat dan berfungsi dengan baik. Maka di perlukan pemeriksaan berkala mulai dari kondisi fisik, volume, masa penggunaan. Untuk penggunaan di perlukan diadakan pelatihan atau sosialisasi penggunaan apar dry chemical powder untuk semua aktifitas di daerah yang berpotensi kebakaran. Pengujian tekan APAR yang sudah diisi dengan media air, selanjutnya diuji secara hydrotest. Dengan memberikan tekanan sebesar 1,5 kali dari tekanan kerja normal yaitu 1,5 x 15 = 30 bar. Pengetesan ini dilakukan selama 30 detik. Setelah pengujian dilakukan, cek apakah ada sisi tabung APAR yang mengalami kebocoran dan penurunan tekanan. Dari hasil uji di tabel mulai tabung no 1 sampai dengan no 10 yaitu mulai dari tekanan terendah 372/26.20 psi/bar dan tertinggi 399/27.51 psi/bar. Maka tabung tersebut masih dapat di gunakan dengan tekanan maximum 30 bar. Jika terjadinya kebocoran serta penurunan tekanan APAR merupakan indikasi bahwa tabung APAR tersebut sudah tidak aman (distorsi) dan tidak layak untuk digunakan. Kata Kunci: , api , kelas , apar , hydrotest, pemadam

This study is to determine the hardness and wear of two original and local brake pads on motorcycle brakes by conducting rockwell hardness and wear tests. This test was conducted at the B4T Bandung Automotive Laboratory with results at a load of 60 Kgf, a steel ball indenter with a diameter of 1/12 inch. The results show that the average value of the local brake pad hardness level is 66.7 HR and the average value of the original brake pad is 84.93 HR proving that the highest level of hardness is found in the original brake pad. Wear testing that the original brake canvas sample initial weight 75 gr with 3 variable testing time namely test 1 around 4 minutes obtained 71 gr with eroded weight 4 gr, test 2 around 8 minutes obtained 69 gr with eroded weight 6 gr, test 3 around 12 minutes with weight 67 gr, test 3 around 12 minutes obtained 67 gr with eroded weight 8 gr local brake canvas initial weight 74 gr with 3 variable testing time namely test 1 around 4 minutes obtained 69 gr with eroded weight 5 gr, test 2 around 8 minutes obtained 60 gr eroded with eroded weight 14 gr, test 3 got 56 gr with eroded weight 18 gr, from both samples the results of wear testing that the original and local brake canvas found that the original canvas wear is harder than the local type of canvas.

Using natural fibres is often recommended as polymer composite materials owing to their potential to reduce the pollution of synthetic material waste. This study aimed to obtain the physical properties of unsaturated polyester resin matrix composite containing calcium carbonate fillers of 15 and 30 parts per hundred weights of the resin and natural pineapple leaf fibre of the amount 20% and 30% of the composite weight. The composite samples were three millimetres thick, with the pineapple leaf fibres arranged in one longitudinal direction. Some parameters observed included density, water absorption, response to fire, hardness, tensile strength, modulus of elasticity, and impact strength. The results showed that adding calcium carbonate filler into the matrix increased the density, water absorption, hardness, and modulus of elasticity of the composite. However, it reduced the flame propagation rate, tensile strength, and impact strength. Also, the use of pineapple leaf fibre contributed to increased water absorption, rate of flame propagation, tensile strength, modulus of elasticity, and impact strength of the composite, but it reduced the density and hardness. As these samples use economical materials, they are likely valuable for building materials that do not require high mechanical properties, especially guttering materials.