As-received fibers

Table I shows that the differential heat of adsorption of n-alkane on "as received" carbon fibers Is low and closely approximates Its heat of liquefaction. This Indicates a low concentration of high energy sites on the "as received" fibers. The differential heat of adsorption on "cleaned fibers, especially T-300, Is greater than on "as received" fibers, suggesting that some of the high energy sites on the carbon fiber surfaces were occupied by physically adsorbed species. GC analysis of desorption products, collected In a liquid nitrogen trap, showed the presence of water and carbon dioxide.

The as-received fiber tows were spread and coated with a layer of BN and then with a layer of SiC both layers were deposited by chemical vapor depositioiL For the fabrication... 

Figure 5.48 The relationship between YM and the filament diameter following hot stretching of the three fiber types. Points for the as received fibers (diameters 10, 6.5 and 5.1 pm) are Included and they lie on the best fit straight lines. Source Reprinted with permission from Isaac DH, Ozbek S, Manufacture of carbon fibers from precursors of various diameters. Mater Manuf Proces, 9(5), 975-998, 1994. Copyright 1994, CRC Press, Boca Raton, Florida.

Fig. 8.8 Statistical distribution of diameters for the as-received fibers of (a) bamboo, (b) coir, (c) curaua, (d) piassava, (e) ramie, (f) sisal. (Adopted from [60-62], with kind permission of the...

Pigure 10 shows the typical commercial performance of LEDs used for optical data communication. Both free-space emission and fiber-coupled devices are shown, the latter exhibiting speeds of <10 ns. Typically there exists a tradeoff between speed and power in these devices, however performance has been plotted as a function of wavelength for purposes of clarity. In communication systems, photodetectors (qv) are employed as receivers rather than the human eye, making radiometric power emitted by the devices, or coupled into an optical fiber, an important figure of merit. 

In a series of human studies at the University of Nebraska, a total of 285 human adults were fed several different fiber sources during experimental periods of 5 to 7 days each. Some subjects received more than one test fiber treatment however, all subjects received at least one fiber source as well as receiving the controlled basal diet during one period which included no added fiber... 

In the single fiber strand technique, a single fiber is used as the source and receiving fiber. The reaction phase is located at the end of the fiber and the separation... 

Although neurons have many shapes and forms, a common pattern is evident.4003 At one end of the elongated cell (Fig. 30-8) is a series of dendrites, thin fibers often less than 1 pm in diameter. The ends of the dendrites form synapses with other neurons and act as receivers of incoming messages. Additional messages come into synapses on the cell body, while... 

Ti(OR)4 and Zr(OR)4 are the most thoroughly studied alkoxides from the point of view of their hydrolytic decomposition. Depending on the hydrolysis technique, different products such as films, fibers, glasses, and powders of Ti02 and Zr02 may be obtained, numerous preparation techniques are described in dozens of patents. On the other hand the physico-chemical aspect of hydrolysis received considerably less attention. 

On their arrival at the OPCW Laboratory, all seal numbers and the end pattern of the fiber-optic seals will be compared to the seal numbers and photographs received from the inspection site, if so requested in the presence of an ISP representative. Unpacking will be performed in a dedicated area for handling of authentic samples in the OPCW Laboratory. The vials containing the authentic sample splits will be weighted but left closed and sealed as received from the inspection site. For dispatch to each designated laboratory, one authentic sample split is packed together with a pre-analyzed control sample and the respective matrix blank in a transport container in the same manner as described above. A... 

The carbon fibers used In this study, supplied by the Union Carbide Co., were 1) T-300 3k (PAN) untreated, unsized and 2) P-55 2k (pitch), untreated, unsized. Fibers were cut Into 2 to 3 mm lengths and packed In 1.2 m glass columns with Inner diameters of A.O 10"3 m. The adsorption was studied on "as received (AR) and "cleaned" (T) fibers. 

Adsorption of n-nonane on both types of "as received" (AR) fibers was studied at 30 0.05°C. In the case of T-300T fibers, the column temperature was maintained constant at 60 0.05°C except for n-nonane adsorption, which was also studied at 50 and 70°C. For P-55T fibers, the column temperature was maintained constant at 75 0.05°C except for n-nonane adsorption, which was also studied at 50, 60 and 70°C. The temperature was controlled with a circulating water bath (Lauda K4R). 

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