No abstract

In the present study, various quenching media were added as cooling media for the quenching after pack carburizing treatment. The aim of this research is to get a suitable cooling medium for pack carburizing quenching treatment to increase the wear resistance of low carbon steel. Many cylindrical specimens for the adhesion wear tests were prepared from the used SS400 steel according to ASTM G99-04 specifications. Two heat treatment processes, namely pack carburizing and quenching were done. Firstly, the specimens are pack-carburized at a temperature of 875 °C, soaking time of 2 hours and quenched. The carburizing agent consists of Pinctada maxima shell powder (PMSP) and corn cob charcoal with a weight ratio of 30:70 %. Different cooling media (water, 10 % NaCl solution, 10 % cane molasses) in the pack carburizing quenching treatment are subjected to different kinds of tests. The hardness test was performed using Vickers micro hardness tester, the wear resistance was used in adhesive wear test, the carbon content was determined and microstructure examination was made using a scanning electron microscope (SEM-EDX). The result showed that all cooling media contributed to an increase in mechanical properties (surface hardness number, wear resistance), carbon content and microstructure change. The use of cooling media in the pack carburizing quenching process generally increases the surface hardness number of the specimen. The highest surface hardness number was 595 kg/mm2, respectively using 10 % cane molasses. The work shows that cane molasses can be used as a cooling medium for pack carburizing quenching of SS400 steel and contributed to the improvement of wear resistance

Wood material is very popular in indonesia and all over the world, there are so many people who use it as their buildings contruction and also for their home tools, because the wood material is strong, long lasting, green living, save and lux. On the other hand the wood material will be mouldy if it meets water, thats why this material is not suitable to be placed in humid or wet places we need a new material that can be used as the subtitution of the wood material. The aim of this research is to know about how to make the composite of cotton/glass hybrid fiber and its mecanical using epoxy matrix, and then compare it with wood product. The wood product that used in this research is mahoni.The composite making is using hand lay-up method and the variety fraction volume of cotton fiber and glass fiber are : 30% : 0%, 25% : 5%, 20% : 10%, 15% : 15%, 10% : 20%, 5% : 25%, 0% : 30 %, the epoxy matrix volume fraction is 70 %, where the orientasion of cotton fiber is rondom and 2 cm in lenght, whereas the orientasion of the glass fiber is equally with fiber lenght up to the lenght of mould. The researcher did some test they are: bending test that based on ASTM D 790 standart, compression test that based on ASTM D 695 standart.The bending strenght’s mean of all volume fraction’s varieties of cotton/glass hybrid fiber composite shows the higher bending strenght than the bending strenght of mahoni which is used as the comparator. Afterwards the pressing strenght’s mean of cotton/glass hybrid fiber composite especially in  20%:10% and 0%:30% fraction volume varieties, which is have the values orderly 37,74 MPa and 47,53 MPa, and it shows the higher pressing strenght than the pressing strenght of mahoni, it is 36,78 MPa. Based on the recearch that have been done we can conclude that the characteristic of mechamical cotton/glass hybrid fiber composite can be used as the (alternative) wood subtitution especially mahoni.

Di Kabupaten Lombok Tengah terdapat area pertanian di sekitar Dam Pengga. Area tersebut mencakup lahan pertanin dari beberapa desa termasuk yang dimiliki sebagian petani Desa Darek. Pengairan sebagian lahan yang dekat dengan batas muka air dam dilakukan secara manual atau dengan pompa irigasi. Jenis pompa yang digunakan umumnya pompa sentrifugal berukuran kecil. Dalam operasionalnya, pompa tersebut perlu mendapat maintanance berkala atau perbaikan bila mengalami kerusakan. Penyuluhan dilakukan dengan target kelompok petani pengguna pompa irigasi agar pompa tersebut dapat dipakai lebih lama. Kelompok target juga diharapkan bisa menjadi agen untuk menyebarluaskan pengetahuan praktis dari hasil penyuluhan kepada petani lain yang tidak mengikuti kegiatan pengabdian. Penyuluhan diikuti anggota kelompok petani muda dari salah satu dusun di Desa Darek. Materi penyuluhan adalah panduan praktis perawatan pompa yang isinya mencakup identifikasi kerusakan umum pompa sentrifugal ukuran kecil. Dengan pedoman tersebut, peserta penyuluhan dapat memperbaiki sendiri pompa jika suatu saat menghadapi kerusakan ringan. Sebagian besar peserta telah dapat memahami isi penyuluhan berbekal materi panduan dan tutorial dengan pendampingan langsung saat penyuluhan.

The development of composite materials in the field of engineering is increasingly being used. This