Total useful life

In the USA, there is the ASTM standards and the well-known General Electric requirements. The total useful life of turbine oil is its most important characteristic. ASTM method D943 (IP 157) measures the life indirectly by assessing the useful life of the oxidation inhibitor contained in the formulation and are often referred to as the TOST life of the oil. Rust prevention is generally assessed by the ASTM D665 (IP 135) method. 

The calculation of internal costs is based on the estimated total useful life of the equipment for determination of the proportional equipment costs per year not including the tax benefits of depreciation. For an expected total useful life of 10 years, a purchase price of 100 000 DM gives proportional machine costs of 10 000 DM/year. It is assumed here that the extent of utilization of the machine remains the same during the whole of its useful life (see also Table 12-1). 

Responsible Care is the incentive sponsored by the Chemical Manufacturers Association (CMA). Any CMA company must embrace the philosophy of continuous improvements of health, safety, and environmental efforts accompanied by an open communication to the pubHc about products and their production. Thus the total impact of any product on the environment, from the extraction of raw materials, their beneftciation, transportation, production of final product, and disposal of the product at the end of its useful life, must be taken into consideration. 

A fourth method of computing depreciation (now seldom used) is the sinking-fund method. In this method, the annual depreciation A is the same for each year of the life of the equipment or plant. The series of equal amounts of depreciation Aq, invested at a fractional interest rate i and made at the end of each year over the life of the equipment or plant of s years, is used to build up a future sum of money equal to (Cpc S). This last is the fixed-capital cost of the equipment or plant minus its salvage or scrap value and is the total amount of depreciation during its useful life. The equation relating i Fc S) and Ao is simply the annual cost or payment equation, written either as... 

Useful life period - Stress related failures dominate and oeeur at random over the total system lifetime - eaused by the applieation of stresses that exeeed the design s... 

Caffeine consumption is primarily due to coffee, tea and soft drinks. In the U.S., it is estimated that coffee contributes to 75% of the total caffeine intake, tea is 15%, and soda with caffeine accounts for 10% 5 chocolate and other caffeine-containing foods and medications contribute relatively little to overall caffeine exposure. Caffeine also varies by sources tea leaves contain 1.5 to 3.5% caffeine kola nuts contain 2% caffeine and roasted coffee beans contain 0.75 to 1.5% caffeine.6 Coffee varies in caffeine content some analyses have estimated that caffeine may range from 0.8 to 1.8%, depending on the type of coffee.7 Crops of coffee, tea, and cocoa are very similar in their production periods and their useful life in production. Typically coffee, tea, and cocoa trees can be productive with crops every 5 years for a total period of 40 years,8 or an estimated 8 yields per tree. 

In the total-life plan the amount of depreciation is obtained by multiplying the total amount that can be depreciated by a fraction. The numerator of this fraction is the number of years of useful life remaining. The denominator is the sum of the digits from one through the total estimated number of years of useful life. The denominator is a constant. 

CNG dispensing nozzles are made from aluminum and stainless steel and no materials compatibility problems have been noted. The mechanical action of fastening the CNG nozzle appears to be the limiting factor in CNG nozzle life, not deterioration due to corrosion from the natural gas. CNG dispensing nozzles have a finite lifetime typically characterized by the total number of refuelings completed. Nozzles should be replaced at the end of their useful life to prevent inadvertent failure. 

The first caverns constructed during the 1960 s and 1970 s used as a starting point the methods employed for sizing salt rock mines (gallery sizes, pillars and chambers). Elastoplasticity provided information about the final suite of the galleries, pillars and chambers (over the total service life). 

The total investment-related costs depend on the price of the membranes and their useful life under operating conditions, which is in practical application 5-8 years, and on the price of the additional plant components and their life. 

The required membrane area A refers actually to a unit cell area that contains a bipolar membrane, and a cation- and an anion-exchange membrane. Since in strong acids and bases the useful life of the bipolar membrane as well as the anion-exchange membrane is rather limited, the stack-related investment costs are dominating the total investment costs. 

The remaining useful life evaluation routine (RULER) is a useful monitoring program for used engine oils. The RULER system is based on a voltammetric method (Jefferies and Ameye, 1997 Kauffman, 1989 and 1994). The data allows the user to monitor the depletation of two additives ZDDP and the phenol/amineH+ antioxidant. The RULER results were compared to other standard analytical techniques, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), total base number (TBN), total acid number (TAN), and viscosity to determine any correlation between the techniques (Jefferies and Ameye, 1997 and 1998). The test concluded that the RULER instrument can... 

To investigate the control factors of welded component s fatigue behaviour, and use the analytical methods for estimating the total fatigue life of welds subjected to variable-amplitude loading histories and surface treatments, in order to find some possible methods to improve the fatigue strength. 

Conventional steam reforming is also restricted to applications in which the size of the locally available supply of hydrocarbon fuel is adequate. Much of the world s total natural gas resources are what is called "static gas," i.e., natural gas resources which are individually so small and so remotely located that they can not be economically pipelined to market. In theory this static gas could be reformed into synthesis gas which could then be made into readily shipped liquids. As discussed by Che and Bredehoft (1995), the minimum size for an economically viable steam reformer based on conventional technology is 5,000,000 standard cubic feet (scf) of hydrogen per day. To give such a minimum size steam reformer a 20-year useful life, the local natural gas resource would need to be relatively large. Studies of the economics of UMR indicate that the process will be satisfactory in small-scale applications. 

Consider the example in which the original cost of a certain piece of equipment is 12,000. The useful-life period is 10 years, and the scrap value at the end of the useful life is 2000. The engineer reasons that this piece of equipment, or its replacement, will be in use for an indefinitely long period of time, and it will be necessary to supply 10,000 every 10 years in order to replace the equipment. He therefore wishes to provide a fund of sufficient size so that it will earn enough interest to pay for the periodic replacement. If the discrete annual interest rate is 6 percent, this fund would need to be 12,650. At 6 percent interest compounded annually, the fund would amount to ( 12,650X1 + 0.06) = 22,650 after 10 years. Thus, at the end of 10 years, the equipment can be replaced for 10,000 and 12,650 will remain in the fund. This cycle could now be repeated indefinitely. If the equipment is to perpetuate itself, the theoretical amount of total capital necessary at the start would be 12,000 for the equipment plus 12,650 for the replacement fund. The total capital determined in this manner is called the capitalized cost. Engineers use capitalized costs principally for comparing alternative choices. ... 

The original cost for a distillation tower is 24,000 and the useful life of the tower is estimated to be 8 years. The sinking-fund method for determining the rate of depreciation is used (see Example 5), and the effective annual interest rate for the depreciation fund is 6 percent. If the scrap value of the distillation tower is 4000, determine the asset value (i.e., total book value of equipment) at the end of 5 years. 

In the application of the sum-of-the-years-digits method, the annual depreciation is based on the number of service-life years remaining and the sum of the arithmetic series of numbers from 1 to n, where n represents the total service life. The yearly depreciation factor is the number of useful service-life years remaining divided by the sum of the arithmetic series. This factor times the total depreciable value at the start of the service life gives the annual depreciation cost. 

The amount accumulated in the fund after a years of useful life must be equal to the total amount of depreciation up to that time. This is the same as the difference between the original value of the property V at the start of the service life and the asset value Va at the end of a years. Therefore,... 

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