Materials attributes

The uncertainty associated with the quotient m/mR can be lowered by weighting relatively high amounts of sample and the reference material. Attributing the same uncertainty. Am, for mass measurements, the relative uncertainty of the quotient mlniR becomes minimal for m/mR equal to unity. The uncertainty in mA/mR)H, however, depends mainly on the uncertainties of m, mA, mR and those associated with current measurements. These last ones depend on the uncertainties associated with the measure of the currents in the overlapping wave, and the peak current of the reference redox process that can be related with m,mA,mR and the respective electrochemical coefficients of response. In practice, reasonable measurements can be obtained when 0.05 < ii/ip(R), i2/ip(R) < 20 whereas the uncertainty in these quantities must be minimal for values close to the unity. 

Identify and control critical raw material attributes, process parameters, and sources of variability. 

Pharmaceutical formulation and process development should provide sufficient information and knowledge to understand and support establishment of the design space, specifications, and manufacturing control. The design space of QbD is defined as the multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality.6 Because multiple variables in formulation and process can be encountered, it is important to use an effective methodology to define the design space. 

Corrosion is due to electrochemical potential differences (galvanic corrosion) between the HAZ/fusion line and the parent material, attributed to the unstable MnS inclusions produced during the welding cycle. It was observed that enhanced corrosion of the weld metal was due to electrochemical potential differences between the weld metal and the base metal, such that the weld metal is anodic in the galvanic couple. The potential difference may only be of the order of perhaps 30-70 mV, but the low surface area ratio of anode to cathode results in high corrosion rates (1-10 mm). (Bond)5... 

Complete cross comparison between the sites is not feasible because the Hajji Firuz phase (ca. 5500 to 4750 B.C.), the Dalma phase (ca. 4750 to 4350 B.C.), and the Pisdeli phase (ca. 4350 to 3550 B.C.) (6) are not represented at every site. All three phases occur at Hajji Firuz, though material from the Pisdeli phase is quite limited. The Dalma phase occurs at Dalma Tepe, with a very limited amount of material attributed to the Hajji Firuz/ Dalma phase transition. Only the Dalma and Pisdeli phases occur at Pisdeli Tepe. Accordingly, temporal comparisons may be made at Hajji Firuz and Pisdeli Tepe, that yield quite different kinds of information. 

Ethylene-styrene interpolymers exhibit a novel balance of properties that are uniquely different from polyethylenes and polystyrenes. In contrast to other ethylene-a-olefin copolymers, ESI display a broad range of material response ranging from semicrystalline, through elastomeric to amorphous. The styrenic functionality and unique molecular architecture of ESI are postulated to be the basis of the versatile material attributes such as processability (shear thinning, melt strength and thermal stability), viscoelastic properties, low-temperature toughness and broad compatibility with other polymers, fillers and low molecular weight materials. 

Ethylene-styrene interpolymers are a novel class of polymers exhibiting a unique combination of material attributes that are not found in polyethylenes,... 

In summary, the study found that the terrestrial and aquatic environments of Mururoa and Fangataufa atolls that are accessible to people contain residual radioactive material attributable to the experiences nucleaires, but at generally very low concentrations which the Study concluded were of no radiological significance. There are, however, some features of note whose radiological implications are examined at the end of the next chapter. 

The chemical industry would offer a great service to clients such as SC Johnson by providing materials that meet positive design criteria and providing appropriate data to support the characterization and prioritization of material attributes. It would also help formulators and product manufacturers assure their customers that the products they are making meet environmentally preferable criteria identified by external markets. 

The Digital Material is a material description based on measurable quantities that provides the necessary link between simulation and experiment. Critical components of the Digital Material, a feature based material description with a statistical description of attributes, include 1) experimental methods that provide initial data for simulations and simulation methods to evolve the material attributes, 2) simulation tools that can be used to build virtual specimens, characterize them and compute material properties, 3) coordinated experiments to verify simulations and to supplement critical data and 4) accuracy assessment techniques for both simulation and experiment. Development of this program will itself require simulations and experiments of a fundamental nature. The output will be a model that will permit virtual experiments to be conducted on a two-phase material of previously selected and characterized microstructure. 

MD simulations showed that the transport rates in nanotubes are orders of magnitude faster than in other materials, attributing the exceptionally high transport rates in nanotubes to the inherent smoothness of the nanotube walls. 

To control the quality of the product, any relationship among the critical raw material attributes, process parameters, and quality attributes for each process should be established dining development. In addition, limits need to be specified for critical process parameters that define the design space where the quality of the product is guaranteed. 

Fig. 7.9 Part and material attributes data for the cave insert...

For the moulding tool the most expensive part to be manufactured is the cave insert, which is a mirror image of the fan grill, as can be seen from Fig. 7.8. The cave insert involves complex manufacture and the material attributes and the handling attributes data of it are shown in Fig. 7.9. The manufacture of the cave insert part is performed by sequence of tasks and these tasks have precedence. The methodology of the software allows this to be done rapidly. The tasks are then analysed for their resource requirements and Fig. 7.10 shows the analysis of Mill task. 

Summary. Copolymers based on ethylene and styrene are a novel class of polymers exhibiting unique combinations of material attributes that are not found in polyethylenes, polystyrenes, or their blends. These copolymers offer unique opportunities for innovative developments in basic polymer chemistry, catalyst and process development, materials science and engineering, and application technology. 

The high-temperature drift characteristic of a resistor is an important material attribute, as it affects the long-term performance of the circuit. A standard test condition is 125°C for 1000 h at normal room humidity. A more aggressive test would be 150°C for 1000 h or 175°C for 40 h. A trimmed thick-film resistor is expected to remain within 1% of the original value after testing under these conditions. 

Focusing on these CQAs, activities progress by considering where within the process the CQAs might be influenced, for instance by parameter settings or incoming material attributes. Here, structured RA tools come into play, ensuring the process in its entirety is considered, with all sources of potential impact on CQAs vetted. 

As discussed in Maynard and Aitken (2007), different situations will require different material attributes—whether surface area, mass, or particle number concentration—to be measured the paper recommends measuring all three where possible. The idea of a universal aerosol sampler enabling the collection of personal exposure to all three of these metrics is explored in this paper and in the Nature paper on the safe handling of nanotechnology written by 13 distinguished nanotechnology experts (Maynard et al., 2006). 

In order to adequately evaluate these complex systems, multivariate data analysis techniques must be used. The examples previously discussed highlight only a few approaches to multivariate data acquisition and analysis. There are many approaches for using these tools to obtain an increased understanding of granulation, and to elicit critical process/material attributes, as well as their relationship with final product quality attributes, for controlling the manufacturing process. 

In terms of innovation, some of the most significant advances have occurred in the area of process analyzers, and there are numerous examples of the application of these tools to obtain a greater understanding of the granulation process. Certainly, once critical process and material attributes have been identified, an appropriate tool for the analysis of these attributes is crucial for timely analysis, as well as ultimately controlling the granulation process. 

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