Spiral development

The ratio is up to ten times higher in NaCl solution than the ratios seen in NaOH or KOH solutions. From this, it is deduced that the striations are due to the remarkable anisotropy involved in the step advancing rate of the growth spirals developing on the m faces The main reason why this anisotropy occurs is understood to be due to the NaCl, which is added as a mineralizer in H O. The hydrothermal solution in which natural rock-crystal grows is, in general, NaCl aqueous solution. 

A qualitative discussion of the spiral development of a new polymer through successively more detailed rounds of synthesis, characterization, and evaluation for utility. As the understanding of the material deepens, its preferred areas for application are made apparent and can be explored specifically. 

Fig. 23 a Transmission electron micrograph of permanganic-etched linear polyethylene. The micrograph shows the spiral development around a screw dislocation in a sample crystallised at 130 °C. Scale bar represents 10 pm. Courtesy of D.C. Bassett. From [105] with permission from Elsevier, UK. b Sketch showing c with respect to the fold surface of the crystal layers around the screw dislocation... 

Figure 4.9 Phytoplankton (P(x,t)) concentrations in excitable waves from system (4.32)-(4.33) for r = K = a = 1, Po = 0.1, b = 10-2, c = 0.56, and D = 5 x 10 3, in two-dimensions. White is P = 0.8 and black is P = 0. Upper row From a localized perturbation to the equilibrium state, the excited state develops and gives rise to a target wave expanding outwards. Times shown are, from left to right, t = 0, 150, and 350. Lower row The initial condition is the middle state in the upper row, but with half of the system reset to the fixed point (P = 0.1, Z = 0.18). Spirals develop from the excited pulse endpoints. The snapshots are taken at the same times from initial condition as above.

The spiral development action plan (SDAP) in-depth - survivability and C4I (command, control, communications, computers and intelligence)... 

Future trends - from spiral development to adaptive acquisition... 

So far the Australian journey towards an integrated soldier system has been described, as well as the various methods chosen to accomplish this, whether by development of an Anstralianbespoke system, the acquisition of a foreign bespoke system/architecture or through a staged spiral development approach. The overall intention was for an integrated soldier system to be provided by the final phase of L125 (Phase 4). 

Department of Defence (2005a). Unclassified LAND 125 Spiral Development Action Plan. Australian Department of Defence, Canberra. Available fiom http //www.defence.gov. au/dmo/lsd/landl25/spiral development action plan v21.p(if [accessed 25 January 2011],... 

Design integrity is the first step to usable systems. It is not known if a design is a good one until its implementation has failed or succeeded. Spiral development (an evolutionary approach) as opposed to waterfall development (where each phase of development is completed before the next phase is begun) helps address some of this issue. Usually, a system design is based on short-term considerations because knowledge is not reused from previous lessons learned. Development, ultimately, is driven toward failure. 

Figure 7.37 Spiral development around a screw dislocation producing diverging lamellae in linear polyethylene. The view is essentially along [001]. Drawn after Bassett, Olley and A1 Reheil (1988).

In the spiral development process, a desired capability is identified, but the end-state requirements are not known atprograminitiation. Requirements are refined through experimentation, demonstration, risk management, and continuous user feedback. Development progresses in incremental spirals of preliminary design, detailed design, and test, but the requirements for future increments depend on user feedback and technology maturation. 

In this methodology, the user is provided the best possible capability within each increment, and continuous user feedback is important. The requirements for future increments are dependent on the feedback from users and technology maturation. It is an iterative process designed to assess the viability of technologies while simultaneously refining user requirements. Spiral development complements an evolutionary approach by continuing in parallel with the acquisition process to speed the identification and development of the technologies necessary for follow-on increments. Each incremental spiral provides the best possible capability. Spiral development is a form of evolutionary acquisition. 

See Concurrent Development Model, Incremental Development Model, Spiral Development Model, and System Life-Cycle Model for additional information. 

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