Darts conception

Polymers which yield extensively under stress exhibit nonlinear stress-strain behavior. This invalidates the application of linear elastic fracture mechanics. It is usually assumed that the LEFM approach can be used if the size of the plastic zone is small compared to the dimensions of the object. Alternative concepts have been proposed for rating the fracture resistance of tougher polymers, like polyolelins, but empirical pendulum impact or dart drop tests are deeply entrenched forjudging such behavior. 

The dart catapult concept is a compromise between the easily constructed but Inefficient rubber powered speargun and the power and accuracy of the bulky traditional crossbow. The use of a triangular baseplate in place of the original prod (bow) will reduce the overall width by 1/3 to 1/2. The easily replaced rubbers eliminate the need for building and maintaining a complex and expensive recurve bow. 

It is a new concept in weaponry, similar to the tranquilizer darts shot from guns. But since those and the guns to shoot them from are unavailable to the public, my Fang will have to do. 

Clarke s reference to eye-beams relies on an understanding of an active eye that emits pneuma to unite with particles projected by the object. This way of seeing also resembles the neo-platonic theory of love - a concept that popular texts, such as The Problems of Aristotle, rendered in elementary form the louer sendeth co[nt]inuall beames of the eie towards that which he loueth. And those beames are like vnto arrowes, because the louer doth dart them into the bodie (sig. Lyv). The evil eye depends on the same principles -vapours are emitted from one person s eye to penetrate the victim s eyes. 

In the 3D concept, we define by an identical method the chest and waist darts in a plan parallel with the front body. The darts lines are then projected perpendicnlarly onto the surface of each ballistic panel (Fig. 8.11(a)). The first two darts of chest and waist are projected on the first ballistic panel nearest to the body (Fig. 8.11(b)). The two following darts on the second panel (Fig. 8.11(c)) are shifted taking into account the thickness of compressed fabric and so on for the other panels (Fig. 8.12). 

Figure 1.7 I The dartboards illustrate the concepts of precision and accuracy, and show the difference between the two terms. The buUs-eye on the target represents the true value of a quantity, and each dart represents a measurement of that quantity. The darts in the left-hand panel are widely scattered and far away Ifom the target this is neither precise nor accurate. In the center panel, the darts are closely bunched but are not close to the target this is good precision but poor accuracy. In the right-hand panel, we see good precision and good accuracy because the darts are closely clustered and close to the target.

A rigorous discussion of probability begins with set theory. On simpler ground, the tools of probability can be acquired by thinking exercises. The time-honored ones appeal to balls drawn from urns, poker hands, thrown darts, and tossed coins [5]. Yet the exercises need not be so macroscopic in character. Spin populations and electron clouds have also been used to illustrate and thus reinforce probability concepts [6,7]. The microscopic nature of such examples makes them easier to imagine than to access by experiment. 

The terms precision and accuracy are often used in discussing the uncertainties of measured values. Precision is a measure of how closely individual measurements agree with one another. Accuracy refers to how closely individual measurements agree with the correct, or "true," value. The analogy of darts stuck in a dartboard pictured in Figure 1.25 A illustrates the difference between these two concepts. 

Dynamic arc recognition and termination (DART) and iieldbus nonincendive concept (FNICO) for fieldbus protection. (A) Dart with charactistic curves, (B) FNICO connection system (for zone 2). 

DART This is a newer concept in IS of the fieldbus system. To understand the system it is better to look at the curve showing how an arc is developed, as shown in Fig. X/3.5.2-2A. According to lEC 60079-11 a circuit is considered intrinsically safe when electrical energy within the apparatus and of interconnecting wiring exposed to the potentially explosive atmosphere is... 

This section on direct analysis in real time (DART) [2] has not been placed at the end of this chapter because it would be inferior to the preceding techniques, but because DART relies on much different phenomena. In fact, DART delivers analytical results very similar to those of DESI, even more so to those of DAPCI or DAPPI, and thus presents an alternative concept of ambient MS. 

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