Filling and solidification of molten metals are very complex and difficult to simulate correctly by conservative methods. For a large industrial application, it needs an alternate approach that is fast, reliable and user-friendly. In current casting industries, product development paradigm is shifting from traditional trial-and-error in the workshop to computer-aided casting design and simulation package by a computer(s). Computer-aided casting simulation plays an important role in the paradigm of new product development by way of modeling entire casting processes and reveals a dynamic behavior of casting scheme in working conditions. This study, highlighting is given on using casting simulation software which helps foundry industries to design and analysis the size and shape of the riser. Intended for simulation simplification in this study, grain size of mold green sand, casting material quality, casting process parameters are deliberated identical for all design schemes. Only the shape and dimensional variances of sprue/risers are taken into considerations for defects analysis. It is found that defects such as micro and shrinkage porosities, and improper solidification, are directly related to gating and risers system. Casting simulation software is used for mold filling and solidification analysis and it is observed that the proposed gating and risers system design will improve casting results with small defects. From this study, the conclusion can be stated that taper sprue design, also acts as a riser, with an additional four small risers that will produce a small fraction of porosity inside of the casting part. Validation of simulation, in the future, will be proved through experimental trials in the foundry shop.

This work is a study of changes in coolant activity due to corrosion products of extended burn-up cycles of 18-24 months duration, in a typical pressurized water reactor, under pH and boric acid variations. It deals with non-linearly changing corrosion rates coupled with pH effects. The CPAIR-P computer program was modified to accommodate for time-dependent rising corrosion and effects of coolant chemistry. These simulations suggest that the effect of an increase in pH value for an extended 24-month cycle on a specific activity, in the form of a decrease in the said activity, is smeared by the rising corrosion. The new saturation values for activity at the end-of-cycle are lower than with a reactor operated at constant low pH/natural boric acid in the coolant. For a non-linear rise in the corrosion rate coupled with a pH rise from 6.9 to 7.4 and the use of enriched boric acid (30%-40%), coolant activity first rises to a peak value during the cycle and then approaches a much smaller saturation value at the end of the cycle, when compared with the activity for the system having a constant low pH value (6.9) in the coolant. In this work, we have shown that the use of enriched boric acid as a chemical shim actually lowers primary coolant activity when higher pH values, rather than natural boric acid, are employed in the coolant. For multiple long-term operating cycles, the saturation value of corrosion product activity increases in the first two cycles and becomes constant in subsequent ones, due to the high operational pH value for enriched boric acid (40%) as a chemical shim

Provision of spare parts for production equipment needs to be prepared with specifications, number of needs and correct time of availability, and especially for critical machining components that require correct and appropriate tactics so as not to disrupt its continuity of production. However, it is not a secret for a production department to make replacement parts that have the same mechanical properties through hardness testing of components that have failed. Through a computer program with an algorithm that is able to read a photo as a result of an indentation emphasis on hardness test, it can be known quickly a roundness diameter and calculate its hardness value which will be converted into one of the mechanical properties of a material so that a profile projector is not needed. Core of this implementation of our community service program is through an assignment scheme for employees of PT. Sri Trang Lingga Palembang, located on road TPA 2, RT. 26, RW. 29, Keramasan Subdistrict, Kertapati, Palembang City, South Sumatra, postal code 30149 is how to provide theoretical and experimental knowledge of the implementation of hardness tests on metal materials by emphasizing use of computer algorithms in reading photos of indentation hardness test results as an alternative to replacement use profile projector tool that is usually used for students of D-IV Mechanical Engineering Production and Maintenance (TMPP) Department of Mechanical Engineering Sriwijaya State Polytechnic to determine size of the indentation diameter emphasis from Brinnel hardness test.

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