STUDI OPTIMALISASI KUALITAS PEMBUATAN PISTON MOTOR BERBASIS MATERIAL PISTON BEKAS

The Foundry technology is the oldest manufacture technology in the world. It is approximately on 4000 BM. Al Quran immortalized in As-Saba at verse 11, �Make you perfect coats of mail, and balance well the rings of chain armour, and work you (men) righteousness. Truly, I am All-Seer of what you do�. Development technology in manufacture can�t be separated by foundry technology and machining technology. Both technologies will be able to produce new innovative and useful products, if they are combined in a development system of technology. Machining technology in Meulaboh, West Aceh is sufficient to support the metal casting industry. Making Piston in industry used metal mould which has press-cast system, but it is possible to make piston with the other method like gravity casting. According to the study literature, the trace piston can be recycled without loss of mechanical and physical properties. It has a good flow and the composition of materials can be changed according to what the needs. So, the raw material is no problem to make pistons. The research has proven its presumption, by controlling the temperature of casting is ± 7200C, the temperature of molding is ± 327.50C, maximum holding time is 30 minutes, using metal kowi and just simple method such as furnace with charcoal has been resulted piston. The result of spectrometer test that the trace material of piston has contains 10.21% Si in the motorcycle piston and 10.9% Si in the car piston after re-melted. So the percentage content of Si mass in trace material of piston is equal with Al-Si AC4B that is the raw material of piston, block gear, and cylinder head according JIS. Maximum tensile strength of piston is 15.8 kg/mm2. The density of piston is between 2567 until 2635 kg/m3. Maximum hardness is 48.42 kg/mm2. So, the general result of this research based on mechanical and physical properties is equal 85% of the standard piston. Therefore, we still have a challenge to improve the quality up to 100%

STUDI PERBANDINGAN PERLAKUAN BAHAN BAKU DAN METODE DISTILASI TERHADAP RENDEMEN DAN KUALITAS MINYAK ATSIRI SEREH DAPUR (Cymbopogon citratus)

Indonesia is rich in plant biodiversity. Indonesia volatile oil development efforts through increased development of one plant of lemon grass, which is one of the essential oil producing plants known as Cymbopogon citratus. Lemongrass essential oil in the chemical industry used as raw materials in the manufacture of cosmetics, perfume, deodorant, deodorant soap, floor cleaners and detergents. The purpose of this study was to determine the highest yield of lemongrass essential oil distillation using the method of water distillation, water-steam, and steam to the treatment of intact leaves and chopped leaves and know the quality of essential oil of lemongrass with the treatment of raw materials and different methods of distillation, the design used by two factors: variation in the treatment of raw material (whole leaves and chopped leaves) and the distillation process variation (distilled water (boiled), water-steam distillation and steam distillation. Data obtained from the analysis of yield, specific gravity, refractive index, and oil content of the compound citral essential (lemongrass oil). This study uses three methods of distillation, the distillation of water, water-steam distillation and steam distillation is carried out on samples of intact leaves and chopped leaves of fresh lemongrass. The results yield calculation and testing of physics and chemistry, as well as in the method of analysis SPSS One-Sample Test Statistics for the lemongrass essential oil products. Based on the results of research on the treatment of raw materials and distillation methods can be concluded that the treatment of raw materials lemongrass intact leaves with water distillation method (boiled) at both the content yield 0.52%, 71.84% citral, specific gravity 0.8967 g/mL, and the refractive index of 1.4905. It is appropriate to mention that SNI 06-39-53-1995 yield 0.3%, the specific gravity of 0.8731 g/mL, and the refractive index of 1.4586. But the content of citral not meet SNI standards are 76.1%, but according to Guenther (2006) which states citral content of between 65% to 85%

STUDI PENURUNAN KADAR ARSEN DARI LIMBAH CAIR LABORATORIUM DENGAN PROSES ELEKTROKOAGULASI

The condition of public health become a basic capital which is very important for the sustainability of Indonesia's human development completely. The important thing to do is reduce the impact of development against environmental degradation and human health. Wastewater laboratory will have a negative impact on the environment if not done in wastewater treatment. Compounds containing arsenic, a contaminant which include in the hazardous and toxic waste. The purpose of this study was to evaluate the effect of variations in voltage and contact time in the process of electrocoagulation to decreased levels of arsenic in wastewater, evaluate the efficiency of variation of voltage and contacts time in the electrocoagulation process toward decreased levels of asenic in waste from the laboratory. The method applied in tn the treatment of liquid arsenic is by electrocoagulation process. Electrocoagulation method is a simple processing technique with materials that are cheap, readily available and easy operation technique, so that people will more easily accept and apply them. The object of this research is the arsenic laboratory wastewater. Electrocoagulation process conducted in a laboratory scale. Thisd process is carried out on variations of voltage (3V, 6V, 9V, and 12 V) and variation of contact time (15 minutes, 30 minutes, 45 minutes, and 60 minutes) to the reduction of arsenic

STUDI PERBANDINGAN PERLAKUAN BAHAN BAKU DAN METODE DISTILASI TERHADAP RENDEMEN DAN KUALITAS MINYAK ATSIRI RIMPANG KUNYIT (Curcuma longae)

Essential oils are known as the flying oil (volatile oil) or the etheric oil (essential oil) is produced from plant oils and are easily vaporized without decomposition. Longae Curcuma or turmeric is one of spices and medicinal plants, native habitat of this plant covers an area of Asia, especially Southeast Asia.Essential oils are widely used in industry as a fragrance or flavoring (flavoring). Turmeric contains a chemical that has a physiological activity, namely: curcuminoid and essential oils. This research is aimed to look for the distillation process and the treatment method of the best raw materials to produce the essential oil of turmeric with high quality Existing research was only at a certain distillation method of distillation methods either boiled, steamed, or vapor as well as the treatment of certain raw materials as well. This research used to see the yield and quality (content Tumerone) but has never been a study comparing treatment-related raw materials and distillation method for the following essential oils. Thus, this study needs to be done. The research is started with the treatment raw materials such as milled turmeric and mashed turmeric and water distillation, water-steam distillation, and steam distillation as well. Otherwise, turmeric essential oil is tested with GC-MS for analyzing chemical and physical properties. The chemical properties such as Tumerone compound content and physical properties such as colour, flavour, optical rotation, density, refractive index, etc. Result of the research indicated that the treatment of raw materials and distillation methods which produced the highest quantity (rendemen) was milled treatment and water distillation, while for the quality (chemical properties) was milled treatment and water-steam distillation. The highest quantity (rendemen) was 0.56% and the highest Tumerone compound content was 74.17%