Capture Source Requirements

Provide traceability between operational safety requirements and captured source requirements. 

Depending on the industry and the complexity of the project, there exists a proliferation of requirements managanent tools that systems engineers may use to allocate requirements and establish traceability. These tools are used to capture source requirements, generate the SRD, and establish requirements traceability matrices (RTMs), which list the traces of requiranents in a top-down and bi-directional path. As the system life cycle matures, inCTeasing effort will be directed toward verification that the demonstrated capability of the systan meets its requirements as expressed in allocated requirements captured in the system specifications. Traceability is achieved when all requirements at a particular level of the system hierarchy have been placed in the Requirements Database, and traced top to bottom as well as in a bi-directional view. Requirements must be traced to the verification program (e.g., plans, procedures, test cases, safety proofs, and reports) to provide closed-loop verification. Traceability should be maintained at aU levels of documentation, as follows ... 

From a practical point of view, the important (and ideal) requirement that we need from an inverse is to be able to recover the original source instance. Concretely, if we apply the mapping M" on some source instance I and then we apply the candidate inverse on the result of M", we would like to obtain the original source instance I. Here, applying a schema mapping M to an instance I means generating the instance chaseM(I)- The next definition captures the requirements of such an inverse. 

Neutron-capture processes require a source of free neutrons, given that neutrons are unstable and decay in 10 minutes. There are two important neutron sources available during He-shell burning in AGB stars ... 

Throughout the Concept stage, systems engineers will extract, clarify, and prioritize all of the written directives captured in the source requirements. These requirements will be expanded by a number of activities designed to break down the broad requirements statements and reveal the need for additional clarification, which will lead to either revision of the written source material or additional requirements. 

Unresolved problems or constraints identified in the capture of source requirements... 

Cerium oxide acts as a catalytic oxidizer in a spinel-based additive (38) that aids SO2 to SO conversion and promotes the required sulfate formation. Bastnasite itself is the most economical source of cerium and can be used directly at 1% as the capture additive (39). 

Table 13.17 lists some of the important considerations for the different fume capture techniques. From the point of view of cost effectiveness, the usual preference is source collection or a low-level hood, provided an acceptable scheme can be developed within the process, operating, and layout constraints. The cost of fume control systems is almost a direct function of the gas volume being handled. Flence, the lower volume requirements for the source capture or low-level hood approach often results in significant capital and operating cost savings for the fume control system. 

The use of a source capture or a direct evacuation system is the most positive form of fume capture. A well-designed system can operate at high fume capture efficiencies. For many of these systems, the captured gas temperature for the processing operation is very high (1000-1500 °C), and gas cooling may be required... 

The advantages of low-level hoods are listed in Table 13.17. The first step is to verify that the general principle of local capture of emissions is acceptable and feasible for the process. The next step is to establish the most efficient hood geometry. In most cases, this involves a balancing of the degree of process interference tolerable against the degree of emission source enclosure required. 

Flow limitations restrict application of the DFI interface for pSFC-MS coupling. pSFC-DFI-MS with electron-capture negative ionisation (ECNI) has been reported [421], The flow-rate of eluent associated with pSFC (either analytical scale - 4.6 mm i.d. - or microbore scale 1-2 mm, i.d.) renders this technique more compatible with other LC-MS interfaces, notably TSP and PB. There are few reports on workable pSFC-TSP-MS couplings that have solved real analytical problems. Two interfaces have been used for pSFC-EI-MS the moving-belt (MB) [422] and particle-beam (PB) interfaces [408]. pSFC-MB-MS suffers from mechanical complexity of the interface decomposition of thermally labile analytes problems with quantitative transfer of nonvolatile analytes and poor sensitivity (low ng range). The PB interface is mechanically simpler but requires complex optimisation and poor mass transfer to the ion source results in a limited sensitivity. Table 7.39 lists the main characteristics of pSFC-PB-MS. Jedrzejewski... 

As mentioned earlier, separation of C02 at concentrated sources is easier than from the environment, and carbon capture at upstream decarbonizes many subsequent economic sectors. However, it does require significant changes in the existing infrastructure of power and chemical plants. Furthermore, approximately half of all emissions arise from small, distributed sources. Many of these emitters are vehicles for which onboard capture is not practical. Thus, unless all the existing automobiles are replaced by either hydrogen-powered fuel cell cars or electric cars, the capture of C02 from the air provides another alternative for small mobile emitters. 

Because the neutron direction is known, the FNAP approach does not require the use of coUimators to focus the incident beam and there is no need to pulse the source. However, as the neutrons are emitted in an essentially isotropic distribution, many neutrons still fail to impact the target bag and neutron shielding is needed in aU directions surrounding the source and bag regions. In addition, the scattering of the neutrons in the shielded material along with the resulting inelastic and capture... 

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