Process structure

The major supply chain processes were oudined in Chap. 1, and are shown in Table 3.4, as customer management, procurement, production, and fulhllment. 

Product design Order management Facilities Delivery route planning 

Demand shaping Contract managemtait Flexibility, automation Tracking of orders in transit 

Preference mapping Channel management Outsourcing quality assurance Information technology 

Pricing Supplier relationship Throughput maximization Third party logistics 

---

Mah, R. S. H., Chemical Process Structures and Information Flows, Butterworth, Reading, Mass., 1990. 

Adam G and Delbrtick M 1968 Reduction of dimensionality in biological diffusion processes Structural Chemistry and Molecular Biology ed A Rich and N Davidson (San Francisco Freeman)... 

Process structures with appropriate quantum or molecular mechanical technique to compute desired properties eg, relative energies, dipole moment, conformer populations, size, shape, etc. 

There are three principal categories of rec tification tests according to Mah Chemical Process Structures and Infoimation Flows, Butter-worths, Boston, 1989, p. 414). These are the global test, the constraint test (nodal test), and the measurement test. There are variations published in the literature, and the reader is referred to the references for discussion of those. 

Because of their unique blend of properties, composites reinforced with high performance carbon fibers find use in many structural applications. However, it is possible to produce carbon fibers with very different properties, depending on the precursor used and processing conditions employed. Commercially, continuous high performance carbon fibers currently are formed from two precursor fibers, polyacrylonitrile (PAN) and mesophase pitch. The PAN-based carbon fiber dominates the ultra-high strength, high temperature fiber market (and represents about 90% of the total carbon fiber production), while the mesophase pitch fibers can achieve stiffnesses and thermal conductivities unsurpassed by any other continuous fiber. This chapter compares the processes, structures, and properties of these two classes of fibers. 

Bishopp, J.A., A brief history of the redux bonding process, structural adhesives in engineering V, 5th Int. Structural Adhesives in Engineering Conference (SAE-V). Bristol, UK, 1998. 

Definition of process objectives Generation of separation core structure Selection of separation sequence and unit operations Addition of further units to the process structure Selection of crystallizer type... 

The results described thus far sketch the synthetic demands for being able to prepare processable, structurally defined PPPs, in which the 7r-conjugalion remains fully intact or is even increased as compared to that of the parent PPP 1 system. The key step in the realization of this principle is the preparation of a PPP in which the aromatic subunits can be obtained in a planar or only slightly twisted conformation in spite of the introduction of substituents. 

Wallenberger, F. T., et al., Advanced Inorganic Fibers Processes, Structures, Properties, Applications, Kluwer, 1999. 

There are three main contributions that structural methods are making to the drug discovery process—structural biology, structure-based design, and structure-based discovery. 

Mah, R.S.H., 1992, Chemical Process Structure and Information Flows , Butterworths, Boston. 

If the release forms a vapor cloud that premixes with air before ignition occurs, and turbulence is developed (for example, by the flame front propagating through a process structure), the flame speed can accelerate sufficiently to cause a blast. This event is referred to as a vapor cloud explosion. In addition to blast effects, radiant heat and flame contact effects may also occur. Flashback to the source may cause a pool and/or jet fire. 

Turbulence is required for the flame front to accelerate to the speeds required for a VCE otherwise, a flash fire will result. This turbulence is typically formed by the interaction between the flame front and obstacles such as process structures or equipment. Turbulence also results from material released explosively or via pressure jets. The blast effects produced by VCEs can vary greatly and are strongly dependent on flame speed. In most cases, the mode of flame propagation is deflagration. Under extraordinary conditions, a detonation with more severe blast effects might occur. In the absence of turbulence, under laminar or near-laminar conditions, flame speeds are too low to produce significant blast overpressure. In such a case, the cloud will merely bum as a flash fire. 

Mah RSH (1990) Chemical Process Structures and Information Flows, Butterworth. 

Free radical polymerization Relatively insensitive to trace impurities Reactions can occur in aqueous media Can use chain transfer to solvent to modify polymerization process Structural irregularities are introduced during initiation and termination steps Chain transfer reactions lead to reduced molecular weight and branching Limited control of tacticity High pressures often required... 

Choi, D. D. White, J, L. Polyolefins Processing, Structure, Development and Properties. (2004) Hanser Gardner Publications, Cincinnati. 

The study of solvated alkali metal allyl species remains a complex topic due to a variety of reorganization processes. Structural data on alkali metal allyl derivatives include [G3H5Li(TMEDA)] 133,139 where solvated lithium ions act as... 

For any particular modeling study several receptors might be present that require different decisions for conservative design. For example, dispersion modeling based on a ground-level release will maximize the consequence for the surrounding community but will not maximize the consequence for plant workers at the top of a process structure. 

Sprinkler systems can cause considerable water damage when activated, depending on the contents of the building or process structure. Statistically, the amount of water damage is never as great as the damage from fires in areas that should have had sprinklers. 

The total index is divided into Chemical and Process Inherent Safety Index. The previous is formed of subindices for reaction heats, flammability, explosiveness, toxicity, corrosiveness and chemical interaction. The latter is formed of subindices for inventory, process temperature, pressure and the safety of equipment and process structure. 

A new approach for computerized Inherent Safety Index is also presented. The index is used for the synthesis of inherently safer processes by using the index as a fitness function in the optimization of the process structure by an algorithm that is based on the combination of an genetic algorithm and case-based reasoning. Two case studies on the synthesis of inherently safer processes are given in the end. 

The intrinsic safety is however affected by both the process equipment and the properties of the chemical substances present in the process. Therefore also the index should reflect this fact. We have included parameters into the list (Table 5) to represent the process aspects of the inherent safety. These parameters are the type of equipment involved and the safety of process structure which describe the process configuration from a system point of view. Also a third parameter to describe the interaction (reactivity) of the chemicals present in the process has been included, since this is an obvious source of risk. 

The chosen meaningful parameters are the following reaction heat, flammability, explosiveness, toxicity, corrosiveness, chemical interaction, inventory, process temperature and pressure, equipment safety and safe process structure (see Table 5). This does not mean that other factors affecting the inherent safety of a process are meaningless. On the contrary they should be considered more detailed in further design stages. 

From Table 6 it can be seen how the selected parameters have a connection to the basic principles of inherent safety. For instance the subindices of equipment safety and safe process structure contain several characteristics of inherent safety such as limitation of effects or tolerance to maloperation. It is practical to include several characteristics into few parameters, since the inherent safety principles are both very broad and overlapping. The philosophy behind them cannot be described just by one process parameter. The selected parameters are discussed in more detail on the following pages. 

Limitation of Effects - safer technical alternatives - safer reaction conditions temperature pressure equipment safety safe process structure pressure temperature chemical interaction... 

Simplification - simplify process facilities safe process structure... 

Making Incorrect Assembly Impossible -choice of equipment, piping and fittings correctly equipment safety safe process structure... 

Ease of Control safe process structure heat of reaction... 

Equipment safety tries to measure the possibility that a piece of equipment is unsafe (Heikkila and Hurme, 1998a). Here equipment includes all major pieces of equipment such as pumps and vessels etc. but not piping, valves or instruments as separate entities. Equipment safety considers the safety of the equipment as such without interactions through the process with other equipment. This latter aspect is described by the safe process structure (Ch. 7.9). However interactions through layout, such as a furnace can be a source of ignition for a leak from other piece of equipment, are considered by the equipment safety. 

---