Damage area

Another application areas of microtomography are biology and agriculture. Fig.4a shows an X-ray transmission image through the tulip bulb in wet conditions. Damaged area can be found in the surface of this bulb. Fig.4b shows the reconstructed cross section with information about depth of damaged volume. 

Hand and power tool cleaning is used on ships mostly for spot repair of damaged areas. Hand tools include scrapers, wire bmshes, and sanders. Electric and pneumatic power tools, which include grinders and needle guns, clean faster and more thoroughly than hand tools. Most power tools have vacuum lines coimected to collect paint debris. 

The production of OH ions according to Eq. (2-17) or (2-19) in pores or damaged areas is responsible for cathodic disbonding [9,10], where the necessary high concentration of OH ions is only possible if counter-ions are present. These include alkali ions, NH and Disbonding due to the presence of Ca ions is... 

In order to choose the type of coating and determine the necessary coating thickness, many practice-oriented tests would have to be carried out in which the evaluation of damage areas and choice of service conditions are not always comparable [42-44]. However, information on the various thickness ranges of the PE coating in Ref. 4 was deduced from such experiments. 

When the part will experience higher temperatures or greater stresses than a patch can normally tolerate, the flush aerodynamic technique is often the solution. This technique consists of removing the damaged area and replacing the plies. 

When one or more plies delaminate, one technique is to remove the damaged area and replace the plies, in the similar manner to the flush aerodynamic technique. Another technique is to inject resin directly into the delaminated area. 

Bonded repair sizes, shapes and configurations vary greatly depending on the type of structure and size and location of damage. Typically the damaged area is removed and replacement details of like material and size are prepared to fit. Larger doublers and possibly triplers are installed over the replacement details to hold them in place and transfer load to them. Fig. 23 shows a typical bonded repair for a small damaged area on honeycomb bonded structure. 

Paint the surfaces of both metals. Avoid painting only the less noble metal because if the coating is damaged severe attack may result at the damaged area. 

Repairs to the coating are made with either hot-melt polyethylene sticks or polyethylene sheet patches with mastic profiling compounds for small damaged areas. Large repair areas are best treated as for field weld joint coating, where either heat-shrink crosslinked polyethylene sleeves or cold-applied self-adhesive laminate tapes are employed. 

Electrochemical tests This group includes the various electrochemical tests that have been proposed and used over the last fifty or so years. These tests include a number of techniques ranging from the measurement of potential-time curves, electrical resistance and capacitance to the more complex a.c. impedance methods. The various methods have been reviewed by Walter . As the complexity of the technique increases, i.e. in the above order, the data that are produced will provide more types of information for the metal-paint system. Thus, the impedance techniques can provide information on the water uptake, barrier action, damaged area and delamination of the coating as well as the corrosion rate and corroded area of the metal. However, it must be emphasised that the more comprehensive the technique the greater the difficulties that will arise in interpretation and in reproducibility. In fact, there is a school of thought that holds that d.c. methods are as reliable as a.c. methods. 

Increased responsiveness to noxious stimuli is termed hyperalgesia. It occurs following injury or disease and encompasses enhanced responses as well as reduced thresholds to a given noxious stimulus. Primary hyperalgesia occurs in the damaged area whereas secondary hyperalgesia occurs in the area surrounding it. 

In the very early phases of the acute inflammatory response most of the cells invading the damaged area are polymorphonuclear neutrophils, also denoted as PMNs, which serve as initial line of defense and source of proinflammatory cytokines. These cells, which usually live for 4-5 days, circulate in the blood until they are attracted by chemokines into injured tissues. Whereas physical injury does not recruit many neutrophils, infections with bacteria or fungi elicit a striking neutrophil response. The characteristic pus of a bacterial abscess is composed mainly of apoptotic (apoptosis) and necrotic PMNs. Emigration of neutrophils from the blood starts with a process denoted as margination where neutrophils come to lie at the periphery of flowing blood cells and adhere to endothelial cells (Fig. 1). L-Selectin is expressed... 

Platelets are the formed elements of the blood which participate in hemostasis. Platelets are enucleated, discoid fragments which arise from mature megakaryocytes in the bone marrow. Under normal circumstances, platelets do not adhere to endothelial surfaces of blood vessels. However, platelets can adhere to damaged areas of blood vessels and become activated in such a way that they can also bind fibrinogen. 

Laboratory cabinets are available in both wood and steel. Educational laboratories often use wood, while industrial laboratories usually prefer steel. Wood cabinets do not have the sterile look of steel, but they are far less resistant to physical abuse. They come prefinished with a wood stain. A damaged area is not difficult to refinish. Wood cabinets have no rust problems, but some users have complained about poor chemical resistance of the interiors. The quiet operation of doors and drawers with no metallic noises is appreciated by many. 

Table 10.9 Various types of ulcers along with their underlying cause. An ulcer may simply be described as a break or cut in the skin or membrane lining the digestive tract which fails to heal. The damaged area may then become inflammed...

Symptoms Bleached-looking or pale brown patches on leaves. Damaged areas may crisp. 

Osteoporosis is a serious matter. Cells known as osteoblasts make bone cells known as osteoclasts degrade bone. It may not be obvious but the action of osteoclasts is important. We do small amounts of damage to our bones in the course of our daily activities. These damaged areas need to be repaired to ensure continued bone strength. The osteoclasts remove the small areas of damaged bone and the osteoblasts fill in the gap with new bone. The damage is repaired and bone strength maintained. 

Stem cells are those, which have the possibility to self-renewal during the whole life of animal or human. The process of regeneration and proliferation in the damaged area is implemented due to the pool of stem cells. Stem cells have the ability of the unlimited division and self-renewal, and also of determination, but not final differentiation. 

Inflammation is a local and early response of a tissue to a noxious stimulus, such as physical injury or infection. It results in an increase in the number of immune cells in the area of damage or infection which kill pathogens, remove damaged or dead cells and initiate the healing process. The well-known characteristics of inflammation are redness, heat, swelling and pain. Redness is due to increased blood flow to the damaged area caused by vasodilation of small arterioles, which facilitates an increase in the number of immune cells in the damaged area and facilitates provision... 

Fig. 8.7. Damage area of 24 ply quasi-isotropic carbon fiber reinforced composite laminates containing different resin matrices. After Srinivasan et al. (1992).

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