Costs structure design

Seismic zone basis must be specified for structural design. Soil data is important, especially for cases where extensive use of foundation piling is required with major cost impact. Availability of aggregate or natural pond stabilization materials near the site will not be considered for early cost estimates, but can be kept in mind for future planning if the project is given the green light. 

First, achieving lower raw material cost than at present is always an important economic factor. When the price for one material comes down relative to another, the point at which we trade-off between the two materials changes because cost is a factor in most designs. That statement is not meant to imply that engineers are not concerned about cost in some designs, but we must emphasize that some particular structures have functional requirements as the most important issue. Can they or can they not do the job Cost is not the primary issue in that case. We would naturally like to have a less-expensive Space Shuttle, but can we do the job that the Space Shuttle is now doing with a lower-cost structure We could use less-expensive materials, but would they be able to hold up, would they survive reentry, and would the astronauts be able to survive If the astronauts would not be able to survive, then clearly you would acknowledge that we must pay the added cost to get the job done, i.e., to ensure their safety. 

The problem of optimizing production from several plants with different cost structures and distributing the products to several distribution centers is common in the chemical industry. Newer plants often yield lower cost products because we learn from the mistakes made in designing the original plant. Due to plant expansions, rather unusual cost curves can result. The key cost factor is the incremental variable cost, which gives the cost per pound of an additional pound of product. Ordinarily, this variable cost is a function of production level. 

Unsaturated polyesters are low-molecular-weight fumarate esters containing various chemical structures designed for their specific cost and performance purposes. The two most important features of unsaturated polyesters are the fumarates, which provide the active sites for radical cross-linking with the diluent monomer and the random, low molecular weight, irregular nature of the rest of the molecule, which provide the necessary solubility in the diluent monomer. The preparation of the polyester thus requires the following considerations ... 

Yet waste elimination continues to elude many companies in every sector, including the refinery section and activity from refinery waste (which is a function of their production system design). It may not matter how a refiner categorizes the waste or how the refiner chooses to pursue waste elimination. One thing remains constant that once identified, waste can be eliminated. There are models and structures that allow a refiner to identify and eliminate waste to increase productivity, and hence cost structures, that have a direct impact on refinery operations and, more than all else, profitability. Waste elimination through identification (by judicious analysis) and treatment subscribe to the smooth operation of a refinery. 

Detailed cost and design studies for both PEFC and SOFC systems at sizes ranging from 5kW to 1 MW were made that point to the fundamental differences between PEFC and SOFC technology that impact the system design and by implication the cost structure. These differences will be discussed in the following paragraphs. 

The large fraction of cost related to balance of plant issues is mainly due to the very small scale of this system, which results in a significant reverse economy of scale. While design work is still ongoing, it is anticipated that the cost structure of this system will change rapidly to reduce the cost of balance of plant further, and further improve the competitiveness of these systems. 

Figure 10.36 Typical cost structures for two processes a) a process that is designed and operated properly, and b) a process that is designed for reduced initial cost. The basis cost has units of US /kg for in-specification product...

As argued in Chapter 2.1.2 this work focuses on production network design. Demand is assumed to be independent of production network design decisions and the cost structure achieved. Also, unlimited quantities of raw materials are assumed to be available. An extensions to include make-or-buy decisions (and possibly vendor selection) is provided to accommodate application cases where sourcing decisions have to be included. 

The more expensive, corrosion-resistant alloys are frequently used as a cladding on carbon steel. If a thick plate is needed for structural strength, as for pressure vessels, the use of clad materials can substantially reduce the cost. The design requirements for pressure vessels with cladding or applied internal linings are given in ASME BPV Code Sec. VIII Div. I Part UCL. 

Typically, thermoplastics, because of their high melt viscosity, require higher temperatures and injection molding pressures, or expensive mold fabrication costs to design multiple gate systems and therefore are not cost effective materials for large parts. In addition to cost, the use of multiple gates may also lead to a less structurally sound part as a result of knit lines. 

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