Functional-unit estimate

The methods for estimating capital investment presented in the preceding sections represent the fundamental approaches that can be used. However, the direct application of these methods can often be accomplished with considerable improvement by considering the fixed-capital investment requirement by parts. With this approach, each identified part is treated as a separate unit to obtain the total investment cost directly related to it. Various forms of compart-mentalization for this type of treatment have been proposed. Included in these are (1) the modular estimate,+ (2) the unit-operations estimated (3) the functional-unit estimate,1 and (4) the average-unit-eost estimate.tt... 

Friction factor, Mooify plot for, 482 Friction in flow systems, 480-488 Functional-unit estimate, 191-192 Furane plastics, 436, 443 Furnaces, specifications for, 17 Future worth, factors for, 223n ... 

Other methods for estimating capital investment consider the fixed-capital investment required as a separate unit. These are known as the functional-unit estimates, the process step scoring method, and the modular estimate. 

Step Count Methods These methods, used for order-of-magnitude estimates, are based on the definition of the functional units required to carry out the process. A functional unit is a signifi-... 

Pumping and heat exchange form part of a functional unit. Tn-process storage is ignored, but large storage requirements for raw materials, intermediates, or products are usually estimated separately. Sometimes there are difficiilties in the identification and definition of the functional units involved in a process. 

Typical methods are those of F. C. Zevnik and R. L. Buchanan [Chem. Eng. Progi , 59, 70-77 (Feb. 1963)] and J. H. Taylor Eng. 6-Proc. Econ., 2, 259-267, 1977). The former is mainly a graphical method of estimating the cost per functional unit (Cp) based on the capacity, the maximum pressure, the maximum temperature, and the materials of construction. The Taylor method requires the determination of the costliness index, which is dependent on the complexity of the process. A simpler method was suggested by S. R. Timms (M.Phil. thesis, Aston University, England, 1980) to give the battery hmits cost for gas phase processes only in U.S. dollars with a Marshall and Swift index of 1000. The simple equation is... 

Abiotic Depletion. This takes account of depletion of all non-renewable resources. The impact is calculated as the sum of the resource used for each functional unit divided by the estimated reserves of that resource. 

This cost is very low, compared to other estimates. This may be due to the fact that Zevnik and Buchanan assume a single-train plant, whereas the plant just designed has two trains. If this assumption is made, the direct investment cost of a functional unit for a 75,000,000 lb/yr plant would be 280,000. Making the same calculations as before, the cost of a 75,000,000 lb/yr plant would be 4,400,000. The cost of two such plants would be 8,800,000. This is still low. 

A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. The Human Genome Project has estimated that humans have between 20,000 and 25,000 genes. 

To estimate inhalation contact exposure, some assumptions must be made which err on the side of conservatism and which should be modified as more complete data become available. It is necessary to know the droplet size spectrum of the spray because the diameter of the droplet influences its movement down the respiratory system (11). The functional unit of the lung is the alveolus, which is the terminal branch in the system. It is presumed that pesticide particles which are soluble in respiratory tract fluid and are 5p or less in diameter will reach the alveolus where they will be readily absorbed through the cells of the alveolar membrane into the pulmonary capillary beds and hence into the circulatory system. A recent review by Lippmann at al. (12) discusses in depth the deposition, retention and clearance of inhaled particles. 

A. V. Bridgewater, The Functional-Unit Approach to Rapid Cost Estimation, AACE Bull, 18(5) 153 (1976). 

Economics The process is designed to function at a much higher level of conversion per pass. This high conversion minimizes the size of the BT columns, and the size of Tatoray process unit, as well as the utility consumption of all of these units. Estimated ISBL costs based on a unit processing feed capacity of 355,000 mtpy (US Gulf Coast site in 2003) ... 

If cost data for a similar process is not available, then an order-of-magnitude estimate can sometimes be made by adding contributions for different plant sections or functional units. 

LCI is the methodology for estimating the consumption of resources, the quantities of wastes, the emissions, the traffic accidents, the noise, etc., that are associated with each stage in a product s life cycle. The material and energy flows are modeled between the processes within a life cycle. The overall models provide mass and energy balances for the product system, its total inputs and outputs into the environment, on a per functional unit basis. 

The functional unit of the kidney is the nephron. Each kidney has been reported to contain between 1 and 1.5 million nephrons, although a 1992 estimate suggests a slightly lower range, with a mean of 600,000 nephrons. The number of nephrons that an individual is born with (the nephron dose ) may determine that individuaTs susceptibility to renal injury. 

Direct comparison between (in atomic units) estimated theoretically from Eq. (9) and from the experimental data requires the knowledge of the line shape function o(to) for investigated molecule. The experimental TPA cross section (in the conventional cm s/photon units) is connected with the via the following equation [108, 109] ... 

The worldwide demand for long-range radar (LRR) devices for vehicles with ACC functions is estimated to reach 1 million units in 2003, climbing to 2.4 million units by 2005, while the worldwide demand for the short-range radar (SRR) sensor function is expected to reach 5.8 million units in 2005, from over 850 k units in 1999 [2],... 

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