Verification of Machinery Salvage Value Function

Salvage value or resale value is one of the cost components of machinery replacement models. Some replacement models exclude salvage value in the build-up of cost. Yet it is the value that is adversely affected by deterioration. Various mathematical formulas for machinery salvage value have been formulated. The formula for salvage value presented by Lake and Muhlemann is of interest. It is presented in an exponential form. The suitability of this function to our industrial environment has to be justified bearing in mind that some assets have little or no secondhand value. To ensure a balanced investigation, efforts are made to obtain salvage values for motor grader, representing large scale industrial environment and photocopier, representing small and medium scale industrial environment. It is difficult to obtain salvage values because records are hardly kept for such values. However, two sets of salvage values are obtained for each of the machines. One set is for the calibration of the salvage value function by Lake and Muhlemann while the other is for comparison between the measured and predicted salvage values. This paper therefore sets out to investigate and verify the suitability of salvage value function formulated by Lake and Muhlemann to our industrial environment. It is hoped that the investigation will lead to a better understanding of the salvage value function for proper application in our industrial environment

Generation of Machinery Deterioration Rates

The effects of deterioration on the resale value of machinery and indeed on the machinery replacement date are yet to be appreciated. Deterioration rates are usually assumed or at best determined by subjective methods as well as methods that are expensive like the popular machinery failure analysis. Most machinery replacement models do not include resale value in the build-up of cost, yet it is the value (component) that is adversely affected by deterioration. The need arises to find simple methods of obtaining reliable values for deterioration rates. This paper provides one of such methods. The first step is to ensure that the generated random numbers are reliable and should pass the statistical test of randomness. There are many ways of generating random numbers. The methods include the congruential, midsquare, manual and RAND table. The computer combines these methods in generating random numbers that are predictable, reproducible and possess the statistical attributes of randomness. In this study the computer is used to generate random numbers which are simple and statistically reliable. The next step is to find a way of converting these random numbers to obtain values for deterioration. The uniform (rectangular) probability distribution readily comes to mind. It possesses a probability density that has inverse value within a range of values and zero elsewhere. This property is exploited in conjunction with the useful life of the machine to convert the random numbers to obtain values for deterioration. This is simple, reliable and cost saving

The Effect of Temperature on the Clarification of Apple (MALUS DOMESTICA) Juice with Pecinase obtained from ASPERGILLUS NIGER

Aspergillus niger is a saprophytic fungus existing ubiquitously in the soil and on decaying vegetation. Various researchers have reported Aspergillus niger as frequently responsible for postharvest decay of fresh fruits such as apples, pears, grapes, melons, onions and some vegetables. The fungus has been implicated in the deterioration of apple fruits with the production of Pectinolytic enzymes during the breakdown of the plant cell wall by microbial attack. The three varieties of apple (Malus domestica) fruits used for this work are commonly referred to as Red, Green and Yellow varieties from their physical appearance. The fruits were obtained from a grocery store along Idiroko road, Ota, Ogun State in Nigeria. The fruits were disinfected and inoculated with a 72-h-old culture of A. niger. Control fruits were inoculated with sterile inoculum. The fruits were incubated at room temperature of 27oC for twelve days. Extracts from the inoculated fruits exhibited appreciable polygalacturonase activity while those from the uninoculated fruits possessed only traces of the enzyme activity. The enzyme obtained from the deteriorated fruits and commercially produced pectinase were applied for the clarification of freshly ripe apple fruits under controlled experimental conditions at different temperatures (20oC, 25oC, 30oC, 35oC, 40oC and 45oC) to investigate the role of pectinase in the clarification of apple juice. The temperature of incubation had different effects on the three varieties of apple fruits studied. The volume of juice was more in the cylinders with the enzyme clarification at all temperatures than that with water. The optimum temperature was at 25oC for the three varieties green and red apples. The commercial pectinase produced more juice than the crude pectinase

Dynamic Programming for Machinery Replacement Models.

Dynamic programming is an optimization technique used in solving problems that exhibit the characteristics of overlapping sub-problems and optimal substructure. Optimal substructure indicates that optimal solutions of sub-problems can lead to the optimal solution of the overall problem. Machinery replacement problems exhibit such properties and therefore can be solved by dynamic programming technique. The technique is simple in application and produces definite solutions to machinery replacement problems. It has this advantage over other optimization techniques like the cumbersome forward/backward algorithm which may produce infinite solutions. This paper demonstrates the use of dynamic programming technique in solving machinery replacement problems of a hypothetical front-end loader and an identified Motor Grader. The choice of hypothetical and measured cost data from the construction industry is deliberate. The focus here is on the versatility of the dynamic programming technique in handling such data from the same industry. It can also be extended to other industries. The result reveals the simplicity and efficiency of dynamic programming technique in solving machinery replacement problems. It also shows the difference between hypothetical and measured data. There is also an indication that the Motor Grader has an appreciable secondhand value. The dynamic programming technique is therefore a good tool for industry managers in making machinery replacement decision