Penetrative impact

Thus we are brought to another frequent vision which involves intense, rapt, unitive awareness of external stimuli. If the eyes are open, this super- reality effect can be visual. The penetrating impact of other stimuli can also set off revelatory imagery. 

The single concept, which is defined and discussed in these articles, that without doubt has had the most penetrating impact on the whole field of quantum chemistry, is the concept of the natural spin orbitals. This concept is, in principle, very simple the set of MOs that makes the first-order density matrix diagonal. Lowdin starts out by defining a hierarchy of reduced density matrices for a general wave function ... 

The distribution pattern of the uranium concentrations in surface soils fit the spatial arrangement of the DU penetrator impact points. Excluding the contamina-... 

A modest DU contribution was suggested only at the heavily shelled site (small-scale area) of the garrison of the former Yugoslavian Army near the town of Djakovica in western Kosovo (about 300 DU rounds fired) where a great variability of uranium concentration (0.11. 26 [ig (g dw) ) was observed [140], These results are in line with the findings of UNEP (0.0565 0.00662 to 6.39 0.342 mg kg for U) [57], which could not find significant contamination of the ground surface or the soil except at localized points of concentrated contamination close to penetrator impact sites or penetrator holes. 

Table 9 Falling weight penetrative impact resistance of self-reinforced polymer composites, as described in the literature... 

Fig. 16 Effect of processing condititms rat the deformation of self-reinforced polypropylene tape-based composites following penetrative impact, (a) Specimen was consolidated at lower temperature and pressure and shows large amounts of ont-of-plane deformation and tape pull-through, (b) Specimen was consolidated at a higher temperature and pressure and shows very localised damage and limited out-of-plane deformatimi. Reproduced with kind permission from Elsevier from [160]...

Thanomsilp, C. and Hogg, P.). (2003) Penetration impact resistance of hybrid composites based on commingled yarn fabrics. Compos. Sci. Technol, 467-482. 

In this paper, the performanees of laser-ultrasound are estimated in order to identify lacks of weld penetration. The laser-ultrasonic technique is applied to cylindrical metallic strucmres (few mm thick) in a single-sided control. The results obtained for different materials (gold-nickel alloy and tantalum) are presented by B-sean views for which the control configuration is discussed with regard to the thermal effects at the laser impact. This testing is performed for different lacks of weld penetration (up to 0.5 mm for a thickness of 2 mm) even in the presence of the weld bead, which corresponds to an actual industrial problem. 

This paper deals with the control of weld depth penetration for cylinders in gold-nickel alloy and tantalum. After introducing the experimental set-up and the samples description, the study and the optimization of the testing are presented for single-sided measurements either in a pulse-echo configuration or when the pump and the probe laser beams are shifted (influence of a thermal phenomenon), and for different kind of laser impact (a line or a circular spot). First, the ultrasonic system is used to detect and to size a flat bottom hole in an aluminium plate. Indeed, when the width of the hole is reduced, its shape is nearly similar to the one of a slot. Then, the optimization is accomplished for... 

Projections of market penetrations and contributions to primary consumption of energy from biomass are subject to much criticism and contain significant errors. However, even though these projections may be incorrect, they are necessary to assess the future role and impact of renewable energy resources, and to help in deciding whether a potential renewable energy resource should be developed. 

Acoustical Louvers. Acoustical louvers are used in building mechanical systems when exterior walls are penetrated for fresh air intake, exhaust, or rehef air, in situations where the impact of HVAC noise is of concern in the surrounding environment. The louvers consist of a series of hoUow sheet metal blades. The bottom faces of the louver blades are perforated and the blades are filled with fibrous sound-absorbing material. Typical acoustical louvers are 20 cm (8 in.) to 30 cm (12 in.) in depth. The amount of insertion loss they provide is limited. 

Automotive and architectural laminates of PVB develop maximum impact strength near 20°C, as shown in Figure 2. This balance is obtained by the plasticizer-to-resin ratio and the molecular weight of the resins. It has been adjusted to this optimum temperature based on environmental conditions and automobile population at various ambient temperatures. The frequency and severity of vehicle occupant injuries vs temperature ranges at the accident location have been studied (5), and the results confirm the selection of the maximum performance temperature and decreasing penetration resistance at temperature extremes. 

Fig. 6. Typical variation of mean penetration height with adhesion (2.27-kg ball, impact at —2° C on 305 x 305-mm laminates 0.40% water, 0.76-mm PVB).

Fig. 1. Deceleration and penetration curves from dynamic impact tester. Time vs distance penetrated (A) and deceleration (B). Distance between vertical...

Water resistance test methods include AATCC 127 (hydrostatic pressure test), AATCC 42 (impact penetration test), and AATCC 35 (rain test). In the hydrostatic pressure test, a sample is subjected to a column of increasing water pressure until leakage occurs. The impact penetration test requires water to be sprayed on the taut surface of a fabric sample from a height of two feet. The fabric is backed by a blotter of predeterrnined weight, which is reweighed after water penetration. The rain test is similar in principle to the impact penetration test. 

One measure of impact resistance is the laminate s mean break height (MBH) (102). In the standard test, there is a 50% probabiHty that a five-pound (2.27-kg) ball will not fall through a laminate if the ball is dropped at the MBH. Typical MBHs for 12 in. (- 30 cm) square laminates prepared with 30 mil (0.76 mm) thick interlayer are 10 ft ( -- 3 m) at 0°F (—18 C) and 15 ft ( -- 4.6 m) at 70°F (2I°C). Figure 2 shows a relationship between adhesion and falling ball penetration resistance measured at 2I°C. 

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