Cover factor

Empirical attempts have been made to relate strip and grab test results, particularly for cotton fabrics, so that if one strength is known, the other can be calculated. The relationship is complex, depending on fiber strength and modulus, yam size and crimp, yam-to-yam friction, fabric cover factor, weave, weight, and other factors (19). 

Geometrical means have unsymmetrical uncertainty intervals which are characterized by a dispersion factor v (see Sect. 4.1.2, Eq. (4.20)) and a covering factor k (see Sect. 4.2). Corresponding results should be given in the form... 

Counselors and therapists have to determine when the client has made sufficient progress to move into this next phase of therapy. The decision whether the client is ready to be moved from formal treatment into aftercare is determined by client progress on the treatment plan. The counselor or therapist uses clinical judgment to ascertain whether the client has made sufficient progress on the plan to warrant movement from formal treatment into aftercare and whether the client is sufficiendy stable in his or her recovery to take this next step toward autonomous recovery. The next section covers factors that counselors and therapists should consider when making the decision to graduate clients from treatment into aftercare. In addition, this chapter provides an overview of what can be expected during this final phase of treatment and therapy for professionals, and for clients and their families. 

A number of reviews of varied quality cover general or special effects of photochemical oxidants on vegetation (Table 11-1). Thomas fairly comprehensively covered the available information on the effects of photochemical oxidants on plants. Middleton gave the first comprehensive coverage of the phytotoxic effects of photochemical oxidants in 1961. A number of excellent reviews have appeared since 1%1. Rich presented an early review of ozone effects. Dugger and associates presented the physiologic and biochemical effects of oxidants on plants. Heck covered factors that influenced the expression of oxidant dam-... 

If the fibres absorb all of the incident radiation, then the only source of transmitted rays is from the spacing between the yams. By definition, the theoretical maximum SPF is the reciprocal of 1 minus the cover factor. 

Figure 14.2 illustrates the relationship between the maximum SPF and the cover factor. Using a SPF value of 50 as the goal, a fabric with a cover factor of 0.98 and composed of fibres that absorb all of the non-reflected UV radiation will provide its wearer with excellent protection against solar UV radiation. 

Interaction of radiation with fabrics of varying cover factors. 

In the literature, one can hnd theoretical and practical studies relating to heat transfer conditions in scraped-surface heat exchangers (19, 54), which cover factors such as specific weight, specific heat, latent heat of crystallization, dry matter content, retention time, and overall heat transfer conditions. 

Conceptually the whole field of iodine nutrition may be subdivided into two broad subdivisions, the process and the impact (or outcome) fields of iodine nutrition, each with its own assessment indicators. The impact side of the iodine nutrition field represents the response of the human body to the iodine delivered to and consumed by the consumer, and therefore follows the process phase sequentially. This response of the human body is usually assessed in terms of impact indicators, such as the median urinary iodine concentration, thyroid size, and blood constituents such as thyroid-stimulating hormone, thyroglobulin, or other thyroid hormones. The process side of iodine nutrition covers factors playing a role in the delivery of iodine to the consumer via iodized salt or via an alternative source, such as processed food, drinking (iodine-containing cleaning agents) used in the dairy industry water or iodophors. 

It can be seen from this that different fiber types of the same linear density but of different densities can have different fiber diameters, so a fiber with a higher density will have a smaller diameter than a fiber of the same linear density but a lower density. This highlights another area where fiber (filament) diameter is also important, and that is in calculating cover factor. Cover factor is simply a number that gives an indication of the extent to which the area of fabric is covered by one set of threads or as a measure of the relative density of packing (i.e., looseness or tightness) of the yarn in the fabric. It is calculated, in the case of woven fabrics, from the equation... 

However, as shown above, filament diameter can be different if the polymer density is different, so the above equations for cover factor can in many cases be only a guide and may need to be modified for density if comparisons arc to be made. Also, of course, in the case of staple fiber yarns particularly, twist factor can have a marked effect on the yarn density and hence on yarn diameter, but as a first approximation the yarn diameter of a staple fiber yarn spun on the cotton system can be found from... 

Oggiano, L., Tro3mikov, O., Konopov, I., Alam, F., Subic, A., 2009. Aerodynamic behaviour of single sport jersey fabrics with different roughness and cover factors. Sports Eng. 12 (1), 23-28. 

A number of other factors emerge as contributory properties of the fabric or armour system. If the yams are loosely woven, there is a greater tendency for projectiles to part the yams and penetrate without fully loading them a process known as windowing. This effect is suppressed if the yams are relatively closely woven often this is described by a cover factor - the ratio of the projected area of the individual yams to the area covered by the yams when woven into fabric. 

The majority of textile systems use the same fabric type throughout their thickness, but there are examples of armour using varied types. For instance, the requirement for high cover factors is oidy for the layers in contact with the projectile, so it may be beneficial to have high cover factor fabric towards the impact face and coarser weave fabric to the rear. A preference for lower cover factor coarse fabric is economic, as cost tends to scale with thread count. 

Cover factor Measure of degree of openness of fabric, measured in both warp and weft directions. At higher values, fabric becomes stiffer, drapes less easily. 

I also talk about chemical reactions in this part. 1 give some examples of the different kinds of chemical reactions you may encounter and show you how to balance them. (You really didn t think I could resist that, did you ) I cover factors that affect the speed of reactions and why chemists rarely get as much product formed as expected. And I discuss electron transfer in the redox reactions involved in electroplating and flashlight batteries. 1 hope that you ll see the light in this part ... 

Cover factor n. The fraction of the surface area that is covered by yarns assuming round yam shape. 

The interspacing and diameter/thickness of the yarn is often used to calculate what is termed the fabric s cover factor , meaning the actual area the solid part of the fabric covers when the fabric is laid on a surface. From a more practical sense, this is the fraction of a fabric surface area that comprises the fibres/filaments. Neglecting the very small interfibre interstices. Fig. 8.24 depicts the projected areas seen in this way for a plain-weave structure, which can be used to obtain a calculated estimate of the fabric porosity. 

It was shown above that the cover factor is directly related to the POA, and it is therefore reasonable to assume that the relation extends to the fabric permeability normal to the plane of the fabric. However, the in-plane permeability is more complex, as it concerns the cross-section area of the fabric. 

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