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This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell’s surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300oC. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

Investment Casting (IC) is a method of produce high quality casting. It is useful to generate complex geometry in casting product, which can’t be achieved by forging, machining, or machining process with excessive material usage. Current, IC pattern is made of wax. The pattern is coated with refractory material. The wax melts away during the molted metal pouring. In the past, it is stipulation that once a foundry used a particular grade of pattern wax, then they couldn’t be replacing by other grade. This was to avoid the risk of dimensional variation of patterns, coupled with a basic fear of change. The pattern wax compounds have been chosen by foundries with numerous considerations, such as: historical record; the wax the only suitable compound at the time; professional recommendation; and copying from another foundry. Inappropriate wax injectors parameter can create low quality pattern and ceramic shell. Nowadays, there are wide ranges of material available as an alternative for the IC wax pattern, which in this paper initially highlighted using Acrylonitrile Butadiene Styrene (ABS) as a replacement of conventional pattern material. The pattern with ABS material can be created by Rapid Prototyping Machine (RPM) that is Fused Deposition Modeling (FDM) technology. The experimental outcomes are: there are crack in the ceramic shell while using smelting chemical method because ABS material pushed out the shell; perfect ceramic shell with ABS pattern smelting while using burn-out method; and burn-out method application can  reduce 3 (three) step in investment casting process.

The challenge for engineer’s orthopedic prosthetic rehabilitation is to find a state of the art in the field, technical or otherwise, that will help their clients who have disabilities. Organ replacement with prostheses is one of the most successful procedures until now. However prostheses are still using standard geometry that has been determined by the manufacturer of the prostheses and it becomes a problem. In addition to the design size that does not fit, long manufacturing process takes time and is expensive also being a problem. Suitability of the prostheses with the patient's body anthropometry and speed of production in the manufacture of the prostheses is very important. In manufacturing, precision and speed of manufacture of the product is something that is possible but requires a high cost, especially in the manufacture of prostheses. By using rapid prototyping technology are available, this research try to develop the customized and rapid manufacturing systems for the manufacture of prostheses, especially for Total Knee Replacement (TKR).

ABSTRACT Six Sigma method is one method of management approaches aimed at making decisions based on facts and based on the use of data using special tools and methodologies. This study deals with the methodology of Six Sigma approach in reducing the incidence of occupational accidents in the collection of solid waste in South Jakarta. The fundamental problem-solving approach is done by following the DMAIC (Define-Measure-Analyze-Improve-Control) in order to reduce the process variation and improvement process results. Analysis of the problem also using some tools such as Pareto diagrams, Fishbone diagrams and Analytical Hierarchy Process. Research conducted at the Department of cleanliness of South Jakarta as research subjects in order to analyze and determine the cause of the problem of workplace accidents solid waste collection. Results show DPU approximately 0.22 and approximately 220000 and a target DPMO sigma level is 3.554. Moreover, the results of AHP calculation using Expert Choice software indicate the most significant factor is the method with 0.392 weights. In addition, the sub-causes of the most dominant in workplace accidents collecting solid waste, such as, lack of safety equipment around 0.833 and pleasant environment around 0.833. Keywords: six sigma, pareto, fishbone, AHP, solid waste management, accident, DKI Jakarta. 

Abstrak. Air merupakan salah satu produk pangan yang dianalisis di laboratorium kimia air dan lingkungan. Salah satu parameter yang dianalisis adalah zat organik. Banyaknya sampel yang masuk tidak sebanding dengan kemampuan analisis dapat menyebabkan keterlambatan hasil uji. Metode Analytical Hierarchy Process diaplikasikan untuk mengevaluasi metode analisis yang digunakan. Alternatif metode yang diuji meliputi metode titrimetri, spektrofotometri, dan total organic carbon (TOC). Responden terdiri dari deputi manajer teknis, koordinator laboratorium, dan dua orang analis senior. Alternatif hasil yang didapat adalah metode TOC. Usulan perbaikan metode analisis berdasarkan alternatif hasil yang didapat, yaitu metode TOC dengan waktu analisis 10-15 menit serta penggunaan CRM untuk validitas hasil analisis.

Kata kunci: organic substance, analytical hierarchy process, titrimetric, spectrophotometry, total

organic carbon.