Bamboo-type

According to Folkers and Unna, the Peruvian ehazuta curare (bamboo type) is made from C. tomentosum R. and P., Annona ambotay Aubl., Aristolochia rumicifolia Mart, and Zucc. and an unidentified plant which is neither a menisperm nor a Stryehnos. Of these four the first was... 

An analysis of the rate of elongation of a wire possessing a bamboo-type grain structure is given in Section 16.1.3. An essential aspect of the analysis is the assumption that the stress-induced atomic transport producing the elongation is diffusion-limited. Now, construct the main framework of a model for the same system in which the atomic transport is source-limited, as indicated below, and explain how the model works. 

Figure 3.3 TEM images of the two common VACNF internal structures (a) herringbone-type nanofiber grown from Ni catalyst and (b) bamboo-type nanofiber grown from Fe catalyst at the same conditions. Reprinted with permission from [4].

Bioelectrochemical sensing of promethazine with bamboo-type mul-tiwalled carbon nanotubes dispersed in calf-thymus double stranded DNA. Bioelectrochemistry, 99, 8-16. 

Dispersion of bamboo type multi-wall carbon nanotubes in calf-thymus double stranded DNA. Colloids Surf., B, 108, 329-336. 

Fig. 8 (a) Advanced morphology of anodically grown Xi02 nanotubes (i) bamboo type ... 

The pulp and paper industries use three types of raw materials, namely, hard wood, soft wood, and nonwood fiber sources (straw, bagasse, bamboo, kenaf, and so on). Hard woods (oaks, maples, and birches) are derived from deciduous trees. Soft woods (spruces, firs, hemlocks, pines, cedar) are obtained from evergreen coniferous trees. 

Traditionally, opium is smoked with a pipe, typically around 20 inches long. Opium pipes are usually made of wood, and the type of wood used often denotes the wealth of the smoker. Poor smokers typically use pipes made from bamboo, while wealthier smokers may have pipes constructed of ebony. About three-quarters down the shaft of the pipe rests the bowl, a hollow structure that can be made of metal, porcelain, or clay, again depending on the quality of the pipe. The hollow pipe is sealed on one end and has an opening on the other, through which the user takes in the smoke. 

What do bamboo stalks, mud bricks, steel-belted radial tires, fiberglass fishing rods, reinforced concrete, and the heat tiles on a space shuttle have in common The answer is that these materials are all composites. A composite is a material consisting of two or more components with overall properties different from and superior to either or any one of the individual components. For example, many pleasure boats today have hulls made of a composite material called reinforced plastic that contains glass, plastic, carbon, or some other type of fiber embedded in plastic. The composite material is stronger, more durable, and less dense than the fibers or plastics of which it is made. 

The form taken by the distortion varies between types of polymer but generally it is helical. With polyolefins a feature resembling the thread of a screw may appear, and with polystyrene the extrudate may form a spiral with other melts, ripples or repetitive kinks like bamboo may be seen. For all melts, at rates well above the critical point, the helical nature becomes obscured by severe distortion which looks quite random. 

Abstract. IR pyrolysis of PAN and PAN based composites yields ordered graphitelike structure as well as several carbon nanostructures. Metal-carbon nanocomposites, in which the nanosized metal particles were introduced into the structure of carbon matrix in the course of IR pyrolysis of composite-precursor on the basis of PAN and metal (Gd, Pt, Ru, Re) compounds were prepared. The carbon phase of metal-carbon nanocomposites was shown to include different types of nano structured carbon particles. Bamboo-like CNT were observed in the structure of pyrolized at 910 and 1000°C composite-precursor based on PAN and GdCl3. At T=1200°C the solid carbon spheres with diameter in the range of 50-360 nm and octahedral carbon particles with the size in the range of 300-350 nm were observed. These nanostructured particles consist of carbon only or they include Gd nanoparticles incapsulated in carbon shell. IR pyrolysis of composite-precursor based on PAN as well as H2PtCl6 and RuC13 or NH4Re04 (Pt Ru(Re)=10 l) allows the preparation of Pt-Ru and Pt-Re alloys nanoparticles with 2[Pg.577]

The carbon phase of obtained metal-carbon nanocomposites was shown to contain different types of nanostructured carbon particles in parallel with main graphite-like structures. Bamboo-like carbon nanotubes (CNT) with 14-30 nm in their outer diameter were observed in structured carbon material when GdCl3 was used as a component of composite-precursor (Fig. 4). In this case IR radiation intensity provides the heating of sample to 910 and 1000°C. 

Fig. 1. Typical flow curve of commercial LPE. There are five characteristic flow regimes (i) Newtonian (ii) shear thinning (iii) sharkskin (iv) flow discontinuity or stick-slip transition in controlled stress, and oscillating flow in controlled rate (v) slip flow. There are three leading types of extrudate distortion (a) sharkskin like, (b) alternating bamboo like in the shaded region, and (c) spiral like on the slip branch. Industrial extrusion of polyethylenes is most concerned with flow instabilities occurring in regimes (iii) to (v) where the three kinds of extrudate distortion must be dealt with. The unit shows the approximate levels of stress where the sharkskin and flow discontinuity occur respectively. There is appreciable molecular weight and temperature dependence of the critical stress for the discontinuity. Other highly entangled melts such as 1,4 polybutadienes also exhibit most of the features illustrated herein...

We have presented a thorough description and discussion about the molecular origin of the second kind (b) - bamboo like extrudate distortion - in the preceding Sect. 8. The present section is devoted to a specific illustration of the molecular origin of the type (a) distortion, i.e., sharkskin, which occurs in a range of stress/rate below the oscillatory flow or stick-slip transition, as indicated in Fig. 1. The next section will provide a brief discussion of the origin of the type (c), often spiral-like distortion. The macroscopic nature of the type (c) distortion was first discussed at least over 20 years ago [75]. Note that when the type (c) spiral distortion occurs on very fine length scales on the extrudate it can be and has sometimes been mistaken as sharkskin. 

The term melt fracture has been applied from the outset [9,13] to refer to various types of visible extrudate distortion. The origin of sharkskin (often called surface melt fracture ) has been shown in Sect. 10 to be related to a local interfacial instability in the die exit region. The alternating quasi-periodic, sometimes bamboo-like, extrudate distortion associated with the flow oscillation is a result of oscillation in extrudate swell under controlled piston speed due to unstable boundary condition, as discussed in Sect. 8. A third type, spiral like, distortion is associated with an entry flow instability. The latter two kinds have often been referred to as gross melt fracture. It is clearly misleading and inaccurate to call these three major types of extrudate distortion melt fracture since they do not arise from a true melt fracture or bulk failure. Unfortunately, for historical reasons, this terminology will stay with us and be used interchangeably with the phase extrudate distortion. ... 

Fig. 4.1.7. Baseline-corrected and normalized FTIR spectra illustrating spectral types G, GS 1-GS 4, and HGS. G Norway spruce (Picea abies)-, GS I (Gnetum venosum) GS 2 lauan (Shorea polysperma), GS 3 dabema (Piptadeniastrum africanum) GS 4 birch (Betula sp.) HGS a bamboo (Bambusa sp.) b barley (Hordeum vulgare). (Instrument FTS 40 Bio-Rad, Digilab, 4cm 1 resolution, 32 scans, KBr pellet technique). According to Faix 1991...

This research showed that bamboo has high tensile, flexural, and straining capacities. The tests also indicated that the strength-to-weight ratios are excellent for tension, compression, and flexure in all types of bamboo (14). However, bamboo has three major weaknesses low modulus, low bond stress, and high water absorption which leads to decay. These weaknesses are the major reasons why bamboo is not used widely in todays modem construction field. Many researchers have attempted to reduce the water absorption potential by using paint (2,6),... 

Numerous factors contribute to the bamboo strength, such as type, size, age, storage conditions and duration, type of test and test procedures,... 

Swelling. Based on previous studies (2, 7, 8), bamboo culm can absorb up to 25% water in the first 24 hr. Figure 8 shows the percent of water absorption vs. soaking time in hours. Four types of bamboo were presented for the first 24 hr, and the percent of absorption varies from 20 to 40%. The general trend for all four types is similar. 

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