Fiber terminology

Finally, for those who have read this chapter as an appetizer, a full menu is provided in the References. 

---

Dietary fiber is the accepted terminology ia the United States for nutritional labeling. Total dietary fiber (I DF) and its subfractions, insoluble dietary fiber (IDF) and soluble dietary fiber (SDF), are defined analytically by official methods (3—5). 

The basic terminology of fiber-reinforced composite laminates will be introduced in the following paragraphs. For a lamina, the configurations and functions of the constituent materials, fibers and matrix, will be described. The characteristics of the fibers and matrix are then discussed. Finally, a laminate is defined to round out this introduction to the characteristics of fiber-reinforced composite laminates. 

OFDs can be divided into two subclasses (1) optical fiber chemical detectors (OFCD) which detect the presence of chemical species in samples, and (2) optical fiber biomolecular detectors (OFBD) which detect biomolecules in samples. Each subclass can be divided further into probes and sensors, and bioprobes and biosensors, respectively. As a result of the rapid expansion of optical research, these terms have not been clearly defined and to date, the terms probe and sensof have been used synonymously in the literature. As the number of publications increases, the terminology should be clarified. Although both probes and sensors serve to detect chemicals in samples, they are not identical. The same situation exists with bioprobes and biosensors. Simply, probes and bioprobes are irreversible to the analyte s presence, whereas sensors and biosensors monitor compounds reversibly and continuously. 

Regardless of terminology, pectin qualifies as fiber under these definitions. Kertesz (52) showed that human saliva, gastric juices, trypsin, and pepsin were ineffective in hydrolyzing pectin. Werch and Ivy (53) demonstrated that pectin passes relatively unchanged through the stomach and ileum. 

Many molecules contain more than one function group (either the same or different). In such cases, condensation reactions involving two or more groups per molecule can lead to the formation of polymers, as mentioned above in the formation of proteins from amino acids (—NH2 and —COOH groups). From the standpoint of terminology, the unit or units that are joined together to produce a polymer are monomers with multiple units possible (dimer, trimer, etc.). An example of a man-made polymer involves the synthesis of polyester fiber, such as Dacron polyester on which the textile industry depends. 

A S-AljOj fiber produced by the sol-gel process became commercially available in the 1970s. This fiber is short in length (3-5 mm) and has a very fine diameter (3 jLm). In textile terminology, such a short fiber is called a staple fiber. This staple fiber carries the trade name SaflBl . It contains about 4% SiOj which serves to stabilize the 6-aIumina phase and also inhibits grain growth. 

In another type of membrane extraction devices, porous polypropylene hollow fibers are used, often in a disposable way, which minimizes carryover problems and reduces costs [26-33]. On the other hand, manual manipulations are needed, limiting the possibility for automation. With these devices, the extraction can be carried out in a static mode, either in large sample volumes, where the extraction is not intended to be complete, or in small volumes aiming for complete extraction. Usually, stirring is applied to increase the speed of mass transfer. Some typical practical arrangements are shown in Figure 12.2. This type of SLM extraction is often called hollow fiber liquid phase microextraction, or three-phase liquid phase microextraction or two-phase liquid phase microextraction but the terminology in this active field of research has not been settled. Also hollow fibers can be connected in flow systems [34,35]. 

ASTM D 3878-95c. Standard Terminology of High-Modulus Reinforcing Fibers and Their Composites. 

Table 3 compares the most commonly used peat classification systems based primarily on degree of decomposition. The U.S. system (Soil Taxonomy, USDA, 1975) and the Canadian system (Day, 1968) are essentially similar except for terminology and are based on the amount of unrubbed or rubbed fiber content. 

The abstracts of the Journal of the Textile Institute 28 are very convenient, once the user has become accustomed to the slight differences in terminology—for example, an important index heading is Manufactured Fibers." These abstracts have annual subject, name, and patent number indexes. 

Fibers, yarns, threads, cords, rope, cloth and other fabricated textile materials and the methods of test, terminology, and definitions relating thereto Textile industry raw materials, auxiliaries and chemical products required for processing and testing... 

STRF Standard Terminology Relating to Fibers, D 123-96 American Society for Materials and Testing... 

---